Light-emitting device and electronic apparatus including the light-emitting device

ABSTRACT

A light-emitting device includes a first electrode, a second electrode facing the first electrode, an interlayer disposed between the first electrode and the second electrode and including an emission layer, a first capping layer, and a second capping layer. A refractive index of the first capping layer is greater than a refractive index of the second capping layer, and the first capping layer and the second capping layer are each an organic layer. An electronic apparatus including the light-emitting device is also provided.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to and benefits of Korean PatentApplication No. 10-2020-0114860 under 35 U.S.C. § 119, filed on Sep. 8,2020 in the Korean Intellectual Property Office, the entire contents ofwhich are incorporated herein by reference.

BACKGROUND 1. Technical Field

Embodiments relate to a light-emitting device and an electronicapparatus including the same.

2. Description of the Related Art

Organic light-emitting devices are self-emission devices that have wideviewing angles, high contrast ratios, short response times, andexcellent characteristics in terms of brightness, driving voltage, andresponse speed, compared to devices in the art.

The organic light-emitting devices may include a first electrodedisposed on a substrate, and a hole transport region, an emission layer,an electron transport region, and a second electrode sequentiallystacked on the first electrode. Holes provided from the first electrodemay move toward the emission layer through the hole transport region,and electrons provided from the second electrode may move toward theemission layer through the electron transport region. Carriers, such asthe holes and the electrons, recombine in the emission layer to produceexcitons. These excitons transition from an excited state to a groundstate to thereby generate light.

SUMMARY

Provided is a device that has increased light emission efficiency byincreasing light extraction efficiency.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the embodiments of the disclosure.

According to an embodiment of the disclosure, a light-emitting devicemay include

a first electrode,

a second electrode facing the first electrode,

an interlayer disposed between the first electrode and the secondelectrode, the interlayer including an emission layer,

a first capping layer, and

a second capping layer,

wherein a refractive index of the first capping layer may be greaterthan a refractive index of the second capping layer, and

the first capping layer and the second capping layer may each be anorganic layer.

In an embodiment, the first capping layer may contact the second cappinglayer.

In an embodiment, the first capping layer may contact the secondelectrode.

In an embodiment, the first capping layer may be disposed outside thesecond electrode.

In an embodiment, the first electrode may be an anode, the secondelectrode may be a cathode, the interlayer may further include a holetransport region disposed between the first electrode and the emissionlayer, and the hole transport region may include a hole injection layer,a hole transport layer, an electron blocking layer, or any combinationthereof.

In an embodiment, the first electrode may be an anode, the secondelectrode may be a cathode, the interlayer may further include anelectron transport region disposed between the emission layer and thesecond electrode, and the electron transport region may include a holeblocking layer, an electron transport layer, an electron injectionlayer, or any combination thereof.

In an embodiment, a refractive index of the first capping layer may bein a range of about 1.7 to about 2.2, at a wavelength of about 550 nm.

In an embodiment, a refractive index of the second capping layer may bein a range of about 1.2 to about 1.7, at a wavelength of about 550 nm.

In an embodiment, a thickness of the second capping layer may be greaterthan a thickness of the first capping layer.

In an embodiment, a thickness of the first capping layer may be in arange of about 60 nm to about 100 nm.

In an embodiment, a thickness of the second capping layer may be in arange of about 40 nm to about 120 nm.

According to another embodiment of the disclosure, provided is anelectronic apparatus including the light-emitting device.

In an embodiment, the electronic apparatus may further include athin-film transistor. The thin-film transistor may include a sourceelectrode and a drain electrode, and the first electrode of thelight-emitting device may be electrically connected to at least one ofthe source electrode and the drain electrode of the thin-filmtransistor.

In an embodiment, the electronic apparatus may further include a colorfilter, a color conversion layer, a touch screen layer, a polarizinglayer, or any combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainembodiments of the disclosure will be more apparent from the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic cross-sectional view illustrating a structure of alight-emitting device according to an embodiment;

FIG. 2 is a schematic cross-sectional view of a light-emitting apparatusaccording to an embodiment of the disclosure; and

FIG. 3 is a schematic cross-sectional view of a light-emitting apparatusaccording to another embodiment of the disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings, wherein like referencenumerals refer to like elements throughout. In this regard, theembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein. Accordingly, theembodiments are merely described below, by referring to the figures, toexplain aspects of the description.

Sizes of elements in the drawings may be exaggerated for convenience ofexplanation. Therefore, as the sizes and thicknesses of components inthe drawings may be arbitrarily illustrated for convenience ofexplanation, the following embodiments of the disclosure are not limitedthereto.

As used herein, the expressions used in the singular such as “a,” “an,”and “the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise.

It should be understood that the terms “comprises,” “comprising,”“includes,” “including,” “have,” “having,” “contains,” “containing,” andthe like are intended to specify the presence of stated features,integers, steps, operations, elements, components, or combinationsthereof in the disclosure, but do not preclude the presence or additionof one or more other features, integers, steps, operations, elements,components, or combinations thereof.

In the description, it will be understood that when an element (aregion, a layer, a section, or the like) is referred to as being “on”,“connected to” or “coupled to” another element, it can be directly on,connected to, or coupled to the other element, or one or moreintervening elements may be disposed therebetween.

As used herein, the term “and/or” includes any and all combinations ofone or more of the associated listed items. For example, “A and/or B”may be understood to mean “A, B, or A and B.” The terms “and” and “or”may be used in the conjunctive or disjunctive sense and may beunderstood to be equivalent to “and/or”.

The term “at least one of” is intended to include the meaning of “atleast one selected from” for the purpose of its meaning andinterpretation. For example, “at least one of A and B” may be understoodto mean “A, B, or A and B.” When preceding a list of elements, the term,“at least one of,” modifies the entire list of elements and does notmodify the individual elements of the list.

It will be understood that, although the terms “first”, “second”, etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the embodiments of theinventive concept.

The terms “below,” “lower,” “above,” “upper,” and the like are used todescribe the relationship of the configurations shown in the drawings.The terms are used as a relative concept and are described withreference to the direction indicated in the drawings.

The terms “about” or “approximately” as used herein is inclusive of thestated value and means within an acceptable range of deviation for therecited value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the recited quantity (i.e., the limitations of themeasurement system). For example, “about” may mean within one or morestandard deviations, or within ±20%, 10%, or 5% of the stated value.

Unless otherwise defined or implied herein, all terms (includingtechnical and scientific terms) used have the same meaning as commonlyunderstood by those skilled in the art to which this disclosurepertains. It will be further understood that terms, such as thosedefined in commonly used dictionaries, should be interpreted as having ameaning that is consistent with their meaning in the context of therelevant art and should not be interpreted in an ideal or excessivelyformal sense unless clearly defined in the specification.

In a general top-emission structure for an organic light-emittingdevice, a total reflection anode electrode is formed on a substrate, anda hole transport layer, an emission layer, an electron transport layer,and a semi-transmissive cathode electrode are sequentially formed on theanode, wherein the hole transport layer, the emission layer, and theelectron transport layer mainly include an organic compound.

When a voltage is applied between the anode and the cathode of theorganic light-emitting device, holes provided from the anode move to theemission layer through the hole transport layer and electrons providedfrom the cathode move to the emission layer through the electrontransport layer.

Carriers (such as holes and electrons) recombine in a region of theemission layer to thereby generate excitons, and these excitons changesfrom an excited state to a ground state to thereby emit light.

Constructive or destructive interference of light occurs according to adistance between the two reflective electrodes and the position of theemission layer, and light is emitted through the cathode, which is asemi-transmissive electrode, based on a resonance phenomenon.

External quantum efficiency (next) of a light-emitting material used inthe organic light-emitting device may be obtained by Equation (1) below.

[Equation (1)]

η_(ext)=η_(int) ×r×ϕ×η _(out-coupling)  (1)

η_(int): internal quantum efficiencyr: charge balance factor,ϕ: radiative quantum efficiencyη_(out-coupling): out coupling efficiency

Recently, due to continuous improvement of light-emitting materials, apint value reaches a limit. Thus, η_(out-coupling) should be improved inorder to further increase light efficiency.

In the organic light-emitting device, light generated in the emissionlayer is not 100% emitted to the outside and is lost through variouspaths such as reabsorption of an organic layer, surface plasmonpolarization (SPP), and waveguide, and thus the light extractionefficiency is known to be about 20%. In other words, 80% of lightemitted in the emission layer is lost.

In order to increase efficiency of the organic light-emitting device,the light extraction efficiency as well as development of materials anddevices themselves should be increased.

According to an embodiment, a light-emitting device may include:

a first electrode;

a second electrode facing the first electrode;

an interlayer disposed between the first electrode and the secondelectrode, the interlayer including an emission layer;

a first capping layer; and

a second capping layer,

wherein a refractive index of the first capping layer may be greaterthan a refractive index of the second capping layer, and

the first capping layer and the second capping layer may each be anorganic layer.

According to an embodiment, the first capping layer may contact thesecond capping layer.

In an embodiment, the first capping layer may contact the second cappinglayer, thereby forming a first capping layer/second capping layerstructure or a second capping layer/first capping layer structure.

In an embodiment, the first capping layer may contact the secondelectrode.

In an embodiment, the first capping layer may be disposed outside thesecond electrode. In an embodiment, the first capping layer may contactthe second electrode, outside the second electrode.

In an embodiment, the first capping layer, the second capping layer, andthe second electrode may contact each other, thereby forming a secondelectrode/first capping layer/second capping layer structure.

In an embodiment, the first electrode may be an anode, the secondelectrode may be a cathode, and the interlayer which is located betweenthe first electrode and the second electrode and includes the emissionlayer may further include a hole transport region disposed between thefirst electrode and the emission layer. The hole transport region mayinclude a hole injection layer, a hole transport layer, an electronblocking layer, or any combination thereof.

In an embodiment, the first electrode may be an anode, the secondelectrode may be a cathode, and the interlayer which is located betweenthe first electrode and the second electrode and includes the emissionlayer may further include an electron transport region disposed betweenthe emission layer and the second electrode. The electron transportregion may include a hole blocking layer, an electron transport layer,an electron injection layer, or any combination thereof.

In an embodiment, a refractive index of the first capping layer may bein a range of about 1.7 to about 2.2, at a wavelength of about 550 nm.

In an embodiment, a refractive index of the second capping layer may bein a range of about 1.2 to about 1.7, at a wavelength of about 550 nm.

In an embodiment, a thickness of the second capping layer may be thickerthan a thickness of the first capping layer.

When the refractive index of each of the first capping layer and thesecond capping layer is within the ranges above and a thickness of thesecond capping layer is greater than a thickness of the first cappinglayer, the light extraction efficiency may be increased.

In an embodiment, a thickness of the first capping layer may be in arange of about 60 nm to about 100 nm.

In an embodiment, a thickness of the first capping layer may be in arange of about 70 nm to about 90 nm.

In an embodiment, a thickness of the second capping layer may be in arange of about 40 nm to about 120 nm.

In an embodiment, a thickness of the second capping layer may be in arange of about 60 nm to about 120 nm.

When a thickness of the second capping layer is greater than a thicknessof the first capping layer and the thickness of the second capping layerand the thickness of the first capping layer are within the rangesabove, the light extraction efficiency may be increased.

In an embodiment, the first capping layer may include a compoundrepresented by Formula 1:

In Formula 1,

R₁ to R₆, Ar₁, and Ar₂ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, a C₁-C₆₀ alkyl group unsubstituted or substituted with at leastone R_(10a), a C₂-C₆₀ alkenyl group unsubstituted or substituted with atleast one R_(10a), a C₂-C₆₀ alkynyl group unsubstituted or substitutedwith at least one R_(10a), a C₁-C₆₀ alkoxy group unsubstituted orsubstituted with at least one R_(10a), a C₃-C₆₀ carbocyclic groupunsubstituted or substituted with at least one R_(10a), a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least oneR_(10a), a C₆-C₆₀ aryloxy group unsubstituted or substituted with atleast one R_(10a), a C₆-C₆₀ arylthio group unsubstituted or substitutedwith at least one R_(10a), —B(Q₁)(Q₂), —C(═O)(Q₁), —Si(Q₁)(Q₂)(Q₃), and—P(═O)(Q₁)(Q₂),

X may be selected from a C₃-C₆₀ carbocyclic group unsubstituted orsubstituted with at least one R_(10a) and a C₁-C₆₀ heterocyclic groupunsubstituted or substituted with at least one R_(10a),

m may be an integer from 1 to 3,

a3 and a4 may each independently be an integer from 1 to 3,

a5 and a6 may each independently be an integer from 1 to 4,

when a3 is 2 or more, R₃(s) may be identical to or different from eachother, when a4 is 2 or more, R₄(s) may be identical to or different fromeach other, when a5 is 2 or more, R₅(s) may be identical to or differentfrom each other, when a6 is 2 or more, R₆(s) may be identical to ordifferent from each other, and

R_(10a) may be:

deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or anitro group;

a C₁-C₆₀ alkyl group, a C₂-C₃₀ alkenyl group, a C₂-C₃₀ alkynyl group, ora C₁-C₆₀ alkoxy group, each unsubstituted or substituted with deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, aC₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂),—B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), —P(═O)(Q₁₁)(Q₁₂), or anycombination thereof;

a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀aryloxy group, or a C₆-C₆₀ arylthio group, each unsubstituted orsubstituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group,a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthiogroup, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁),—S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or any combination thereof; or

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₂₁), or —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂-1 to Q₂₃, and Q₃₁ to Q₃₃ may eachindependently be: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxylgroup; a cyano group; a nitro group; a C₁-C₆₀ alkyl group; a C₂-C₃₀alkenyl group; a C₂-C₃₀ alkynyl group; a C₁-C₆₀ alkoxy group; or aC₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, eachunsubstituted or substituted with deuterium, —F, a cyano group, a C₁-C₆₀alkyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a biphenyl group, orany combination thereof.

In an embodiment, R₃ to R₆ may each independently be hydrogen ordeuterium.

In an embodiment, R₁, R₂, Ar₁, and Ar₂ may each independently be aC₆-C₆₀ aryl group unsubstituted or substituted with at least oneR_(10a).

In an embodiment, X may be a C₆-C₆₀ arylene group unsubstituted orsubstituted with at least one R_(10a).

In an embodiment, the second capping layer may include a compoundrepresented by Formula 2:

In Formula 2,

R₁₁ to R₂₅ may each independently be selected from hydrogen, deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, aC₁-C₆₀ alkyl group unsubstituted or substituted with at least oneR_(10a), a C₂-C₆₀ alkenyl group unsubstituted or substituted with atleast one R_(10a), a C₂-C₆₀ alkynyl group unsubstituted or substitutedwith at least one R_(10a), a C₁-C₆₀ alkoxy group unsubstituted orsubstituted with at least one R_(10a), a C₃-C₆₀ carbocyclic groupunsubstituted or substituted with at least one R_(10a), a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least oneR_(10a), a C₆-C₆₀ aryloxy group unsubstituted or substituted with atleast one R_(10a), a C₆-C₆₀ arylthio group unsubstituted or substitutedwith at least one R_(10a), —B(Q₁)(Q₂), —C(═O)(Q₁), —Si(Q₁)(Q₂)(Q₃), and—P(═O)(Q₁)(Q₂),

two neighboring substituents of R₁₁ to R₁₅ may be connected to form aring group, two neighboring substituents of R₁₆ to R₂₀ may be connectedto form a ring group, or two neighboring substituents of R₂₁ to R₂₅ maybe connected to form a ring group, and

R_(10a) may be:

deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or anitro group;

a C₁-C₆₀ alkyl group, a C₂-C₃₀ alkenyl group, a C₂-C₃₀ alkynyl group, ora C₁-C₆₀ alkoxy group, each unsubstituted or substituted with deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, aC₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂),—B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), —P(═O)(Q₁₁)(Q₁₂), or anycombination thereof;

a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀aryloxy group, or a C₆-C₆₀ arylthio group, each unsubstituted orsubstituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group,a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthiogroup, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁),—S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or any combination thereof; or

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are eachindependently: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group;a cyano group; a nitro group; a C₁-C₆₀ alkyl group; a C₂-C₆₀ alkenylgroup; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; or a C₃-C₆₀carbocyclic group or a C₁-C₆₀ heterocyclic group, each unsubstituted orsubstituted with deuterium, —F, a cyano group, a C₁-C₆₀ alkyl group, aC₁-C₆₀ alkoxy group, a phenyl group, a biphenyl group, or anycombination thereof.

In an embodiment, the ring group may be represented by Formula 2-1.

In Formula 2-1,

Y may be —N(R₃₁) or —C(R₃₂)(R₃₃), and

R₃₁ to R₃₃ may each independently be selected from hydrogen, deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a nitro group, a C₁-C₆₀ alkyl groupunsubstituted or substituted with at least one R_(10a), a C₃-C₆₀carbocyclic group unsubstituted or substituted with at least oneR_(10a), and a C₁-C₆₀ heterocyclic group unsubstituted or substitutedwith at least one R_(10a).

R₃₂ and R₃₃ may be optionally connected to form a ring,

a21 may be an integer from 1 to 4,

* indicates a binding site to a neighboring atom, and

R_(10a) is the same as described above.

In an embodiment, when a21 is an integer from 2 to 4, each of R₂₁(S) maybe the same or different from each other.

In an embodiment, a ring of Formula 2-1 may be fused to at least one ofthree phenyl groups linked to N in Formula 2.

The second capping layer includes the compound of Formula 2, arefractive index of which is relatively low.

In an embodiment, Formula 2 may include a C₁-C₆₀ alkyl group moietyunsubstituted or substituted with at least one R_(10a), a C₃-C₁₀cycloalkyl group moiety unsubstituted or substituted with at least oneR_(10a), a fluorene moiety unsubstituted or substituted with at leastone R_(10a), or a spiro-bifluorene moiety unsubstituted or substitutedwith at least one R_(10a). Formula 2 includes the moieties, and thus arefractive index of the second capping layer may be relatively low.

In an embodiment, the first capping layer may include one of followingCompounds:

In an embodiment, the second capping layer may include one of followingCompounds:

In an embodiment, the emission layer may be a phosphorescent or afluorescent emission layer. In an embodiment, the emission layer may bea phosphorescent emission layer. In an embodiment, the emission layermay be a fluorescent emission layer.

According to another aspect, provided is an electronic apparatusincluding the light-emitting device. The electronic apparatus mayfurther include a thin-film transistor. In an embodiment, the electronicapparatus may further include a thin-film transistor including a sourceelectrode and a drain electrode, and the first electrode of thelight-emitting device may be electrically connected to the sourceelectrode or the drain electrode. The electronic apparatus may furtherinclude a color filter, a color conversion layer, a touch screen layer,a polarizing layer, or any combination thereof. A further detaileddescription of the electronic apparatus is the same as described in thespecification.

The term “interlayer” as used herein refers to a single layer and/or alllayers located between the first electrode and the second electrode ofthe light-emitting device. A material included in the “interlayer” maybe an organic material, an inorganic material, or any combinationthereof.

[Description of FIG. 1]

FIG. 1 is a schematic cross-sectional view of a light-emitting device 10according to an embodiment. The light-emitting device 10 includes afirst electrode 110, an interlayer 130, and a second electrode 150.

hereinafter, a structure of the light-emitting device 10 according to anembodiment and a method of manufacturing the light-emitting device 10will be described in connection with FIG. 1.

[First Electrode 110]

In FIG. 1, a substrate may be additionally located under the firstelectrode 110 or above the second electrode 150. The substrate may be aglass substrate or a plastic substrate. The substrate may be a flexiblesubstrate. In embodiments, the substrate may include plastics withexcellent heat resistance and durability, such as polyimide,polyethylene terephthalate (PET), polycarbonate, polyethylenenaphthalate, polyarylate (PAR), polyetherimide, or any combinationthereof.

The first electrode 110 may be formed by, for example, depositing orsputtering a material for forming the first electrode 110 on thesubstrate. When the first electrode 110 is an anode, a high workfunction material that can easily inject holes may be used as a materialfor forming the first electrode 110.

The first electrode 110 may be a reflective electrode, asemi-transmissive electrode, or a transmissive electrode. When the firstelectrode 110 is a transmissive electrode, a material for forming thefirst electrode 110 may include indium tin oxide (ITO), indium zincoxide (IZO), tin oxide (SnO₂), zinc oxide (ZnO), or any combinationthereof. In embodiments, when the first electrode 110 is asemi-transmissive electrode or a reflective electrode, magnesium (Mg),silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca),magnesium-indium (Mg-ln), magnesium-silver (Mg—Ag), or any combinationthereof may be used as a material for forming the first electrode 110.

The first electrode 110 may have a single-layered structure consistingof a single layer or a multi-layered structure including multiplelayers. In an embodiment, the first electrode 110 may have athree-layered structure of ITO/Ag/ITO.

[Interlayer 130]

The interlayer 130 is located on the first electrode 110. The interlayer130 includes an emission layer.

The interlayer 130 may further include a hole transport region locatedbetween the first electrode 110 and the emission layer and an electrontransport region located between the emission layer and the secondelectrode 150.

The interlayer 130 may further include metal-containing compounds suchas organometallic compounds, inorganic materials such as quantum dots,and the like, in addition to various organic materials.

In embodiments, the interlayer 130 may include, i) two or more emittingunits sequentially stacked between the first electrode 110 and thesecond electrode 150 and ii) a charge generation layer between the twoemitting units. When the interlayer 130 includes the emitting units andthe charge generation layer, the light-emitting device 10 may be atandem light-emitting device.

[Hole Transport Region in Interlayer 130]

The hole transport region may have: i) a single-layered structureconsisting of a single layer consisting of a single material, ii) asingle-layered structure consisting of a single layer includingdifferent materials, or iii) a multi-layered structure includingmultiple layers including different materials.

The hole transport region may include a hole injection layer, a holetransport layer, an emission auxiliary layer, an electron blockinglayer, or any combination thereof.

For example, the hole transport region may have a multi-layeredstructure including a hole injection layer/hole transport layerstructure, a hole injection layer/hole transport layer/emissionauxiliary layer structure, a hole injection layer/emission auxiliarylayer structure, a hole transport layer/emission auxiliary layerstructure, or a hole injection layer/hole transport layer/electronblocking layer structure, wherein, in each structure, layers are stackedsequentially from the first electrode 110.

The hole transport region may include a compound represented by Formula201, a compound represented by Formula 202, or any combination thereof:

In Formulae 201 and 202,

L₂₀₁ to L₂₀₄ may each independently be a C₃-C₆₀ carbocyclic groupunsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least oneR_(10a),

L₂₀₅ may be *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a C₁-C₂₀ alkylene groupunsubstituted or substituted with at least one R_(10a), a C₂-C₂₀alkenylene group unsubstituted or substituted with at least one R_(10a),a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at leastone R_(10a), or a C₁-C₆₀ heterocyclic group unsubstituted or substitutedwith at least one R_(10a),

xa1 to xa4 may each independently be an integer from 0 to 5,

xa5 may be an integer from 1 to 10, and

R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be a C₃-C₆₀ carbocyclicgroup unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least oneR_(10a),

R₂₀₁ and R₂₀₂ may optionally be linked to each other, via a single bond,a C₁-C₅ alkylene group unsubstituted or substituted with at least oneR_(10a), or a C₂-C₅ alkenylene group unsubstituted or substituted withat least one R_(10a), to form a C₈-C₆₀ polycyclic group unsubstituted orsubstituted with at least one R_(10a) (for example, a carbazole group orthe like) (for example, refer to the following Compound HT16),

R₂₀₃ and R₂₀₄ may optionally be linked to each other, via a single bond,a C₁-C₅ alkylene group unsubstituted or substituted with at least oneR_(10a), or a C₂-C₅ alkenylene group unsubstituted or substituted withat least one R_(10a), to form a C₈-C₆₀ poly cyclic group unsubstitutedor substituted with at least one R_(10a), and

na1 may be an integer from 1 to 4.

In an embodiment, Formulae 201 and 202 may each include at least one ofgroups represented by Formulae CY201 to CY217:

Regarding Formulae CY201 to CY217, R_(10b) and R_(10c) are the same asdescribed in connection with R_(10a), ring CY201 to ring CY204 may eachindependently be a C₃-C₂₀ carbocyclic group or a C₁-C₂₀ heterocyclicgroup, and at least one hydrogen in Formula CY201 to CY217 may beunsubstituted or substituted with at least one R_(10a) described herein.

In an embodiment, ring CY201 to ring CY204 in Formulae CY201 to CY217may each independently be a benzene group, a naphthalene group, aphenanthrene group, or an anthracene group.

In an embodiment, Formulae 201 and 202 may each include at least one ofgroups represented by Formulae CY201 to CY203:

In embodiments, Formula 201 may include at least one of groupsrepresented by Formulae CY201 to CY203 and at least one of groupsrepresented by Formulae CY204 to CY217.

In embodiments, in Formula 201, xa1 is 1, R₂₀₁ is a group represented byone of Formulae CY201 to CY203, xa2 is 0, R₂₀₂ is a group represented byone of Formulae CY204 to CY207.

In embodiments, each of Formulae 201 and 202 may not include a grouprepresented by one of Formulae CY201 to CY203.

In embodiments, each of Formulae 201 and 202 may not include a grouprepresented by one of Formulae CY201 to CY203 and may include at leastone of groups represented by Formulae CY204 to CY217.

In an embodiment, each of Formulae 201 and 202 may not include a grouprepresented by one of Formulae CY201 to CY217.

In an embodiment, the hole transport region may include one of CompoundsHT1 to HT44, m-MTDATA, TDATA, 2-TNATA, NPB(NPD), β-NPB, TPD, Spiro-TPD,Spiro-NPB, methylated-NPB, TAPC, FIMTPD,4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA),polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/camphor sulfonic acid (PANI/CSA),polyaniline/poly(4-styrenesulfonate) (PANI/PSS), or any combinationthereof:

A thickness of the hole transport region may be in a range of about 50 Åto about 10,000 Å. For example, the thickness of the hole transportregion may be in a range of about 100 Å to about 4,000 Å. When the holetransport region includes a hole injection layer, a hole transportlayer, or any combination thereof, a thickness of the hole injectionlayer may be in a range of about 100 Å to about 9,000 Å, and a thicknessof the hole transport layer may be in a range of about 50 Å to about2,000 Å. For example, the thickness of the hole injection layer may bein a range of 100 Å to about 1,000 Å. For example, the thickness of thehole transport layer may be in a range of about 100 Å to about 1,500 Å.When the thicknesses of the hole transport region, the hole injectionlayer, and the hole transport layer are within these ranges,satisfactory hole transporting characteristics may be obtained without asubstantial increase in driving voltage.

The emission auxiliary layer may increase light-emission efficiency bycompensating for an optical resonance distance according to thewavelength of light emitted by an emission layer, and the electronblocking layer may block the flow of electrons from an electrontransport region. The emission auxiliary layer and the electron blockinglayer may include the materials as described above.

[p-Dopant]

The hole transport region may further include, in addition to thesematerials, a charge-generating material for improvement of conductiveproperties. The charge-generating material may be uniformly ornon-uniformly dispersed in the hole transport region (for example, inthe form of a single layer of a charge-generating material).

The charge-generation material may be, for example, a p-dopant.

In an embodiment, a lowest unoccupied molecular orbital (LUMO) energylevel of the p-dopant may be equal to or less than about −3.5 eV.

In an embodiment, the p-dopant may include a quinone derivative, a cyanogroup-containing compound, element EL1 and element EL2-containingcompound, or any combination thereof.

Examples of the quinone derivative may include TCNQ and F4-TCNQ.

Examples of the cyano group-containing compound may include FIAT-CN anda compound represented by Formula 221 below.

In Formula 221,

R₂₂₁ to R₂₂₃ may each independently be a C₃-C₆₀ carbocyclic groupunsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least oneR_(10a), and

at least one of R₂₂₁ to R₂₂₃ may each independently be a C₃-C₃₀carbocyclic group or a C₁-C₆₀ heterocyclic group, each substituted with:a cyano group; —F; —Cl; —Br; —I; a C₁-C₂₀ alkyl group substituted with acyano group, —F, —Cl, —Br, —I, or any combination thereof; or anycombination thereof.

Regarding the compound containing element EL1 and element EL2, elementEL1 may be metal, metalloid, or a combination thereof, and element EL2may be a non-metal, metalloid, or a combination thereof.

Examples of the metal may include: an alkali metal (for example, lithium(Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), or thelike); an alkaline earth metal (for example, beryllium (Be), magnesium(Mg), calcium (Ca), strontium (Sr), barium (Ba), or the like); atransition metal (for example, titanium (Ti), zirconium (Zr), hafnium(Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr),molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium(Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh),iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu),silver (Ag), gold (Au), or the like); a post-transition metal (forexample, zinc (Zn), indium (In), tin (Sn), or the like); and alanthanide metal (for example, lanthanum (La), cerium (Ce), praseodymium(Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu),gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium(Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), or the like).

Examples of the metalloid may include silicon (Si), antimony (Sb), andtellurium (Te).

Examples of the non-metal may include oxygen (O) and halogen (forexample, F, Cl, Br, I, etc.).

In an embodiment, examples of the compound containing element EL1 andelement EL2 may include metal oxide, metal halide (for example, metalfluoride, metal chloride, metal bromide, or metal iodide), metalloidhalide (for example, metalloid fluoride, metalloid chloride, metalloidbromide, or metalloid iodide), metal telluride, or any combinationthereof.

Examples of the metal oxide may include tungsten oxide (for example, WO,W₂O₃, WO₂, WO₃, or W₂O₅), vanadium oxide (for example, VO, V₂O₃, VO₂, orV₂O₅), molybdenum oxide (MoO, Mo₂O₃, MoO₂, MoO₃, or Mo₂O₅), and rheniumoxide (for example, ReO₃).

Examples of the metal halide may include alkali metal halide, alkalineearth metal halide, transition metal halide, post-transition metalhalide, and lanthanide metal halide.

Examples of the alkali metal halide may include LiF, NaF, KF, RbF, CsF,LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI,RbI, and CsI.

Examples of the alkaline earth metal halide may include BeF₂, MgF₂,CaF₂, SrF₂, BaF₂, BeCh, MgCh, CaCh, SrCh, BaCh, BeBr₂, MgBr₂, CaBr₂,SrBr₂, BaBr₂, Beb, Mgb, Cab, Srb, and Bah.

Examples of the transition metal halide may include titanium halide (forexample, TiF₄, TiCl₄, TiBr₄, or TiI₄), zirconium halide (for example,ZrF₄, ZrCl₄, ZrBr₄, or ZrI₄), hafnium halide (for example, HfF₄, HfCl₄,HfBr₄, or HfI₄), vanadium halide (for example, VF₃, VCl₃, VBr₃, or VI₃),niobium halide (for example, NbF₃, NbCl₃, NbBr₃, or NbI₃), tantalumhalide (for example, TaF₃, TaCl₃, TaBr₃, or TaI₃), chromium halide (forexample, CrF₃, CrCl₃, CrBr₃, or CrI₃), molybdenum halide (for example,MoF₃, MoCl₃, MoBr₃, or MoI₃), tungsten halide (for example, WF₃, WCl₃,WBr₃, or WI₃), manganese halide (for example, MnF₂, MnCl₂, MnBr₂, orMnI₂), technetium halide (for example, TCF₂, TCCl₂, TcBr₂, or TcI₂),rhenium halide (for example, ReF₂, ReCl₂, ReBr₂, or ReI₂), iron halide(for example, FeF₂, FeCl₂, FeBr₂, or FeI₂), ruthenium halide (forexample, RuF₂, RuCl₂, RuBr₂, or RuI₂), osmium halide (for example, OsF₂,OsCl₂, OsBr₂, or OsI₂), cobalt halide (for example, CoF₂, CoCl₂, CoBr₂,or CoI₂), rhodium halide (for example, RhF₂, RhCl₂, RhBr₂, or RhI₂),iridium halide (for example, IrF₂, IrCl₂, IrBr₂, or IrI₂), nickel halide(for example, NiF₂, NiCl₂, NiBr₂, or NiI₂), palladium halide (forexample, PdF₂, PdCl₂, PdBr₂, or PdI₂), platinum halide (for example,PtF₂, PtCl₂, PtBr₂, or PtI₂), copper halide (for example, CuF, CuCl,CuBr, or CuI), silver halide (for example, AgF, AgCl, AgBr, or Agl), andgold halide (for example, AuF, AuCl, AuBr, or AuI).

Examples of the post-transition metal halide may include zinc halide(for example, ZnF₂, ZnCl₂, ZnBr₂, or ZnI₂), indium halide (for example,Inb), and tin halide (for example, SnI₂).

Examples of the lanthanide metal halide may include YbF, YbF₂, YbF₃,SmF₃, YbCl, YbCl₂, YbCls SrnCh, YbBr, YbBr₂, YbBr₃SmBr₃, YbI, YbI₂,YbI₃, and SmI₃.

Examples of the metalloid halide may include antimony halide (forexample, SbCl₅).

Examples of the metal telluride may include alkali metal telluride (forexample, Li₂Te, Na₂Te, K₂Te, Rb₂Te, orCs₂Te), alkaline earth metaltelluride (for example, BeTe, MgTe, CaTe, SrTe, or BaTe), transitionmetal telluride (for example, TiTe₂, ZrTe₂, FlfTe₂, V₂Te₃, Nb₂Te₃,Ta₂Te₃, Cr₂Te₃, Mo₂Te₃, W₂Te₃, MnTe, TcTe, ReTe, FeTe, RuTe, OsTe, CoTe,RhTe, IrTe, NiTe, PdTe, PtTe, Cu₂Te, CuTe, Ag₂Te, AgTe, or Au₂Te),post-transition metal telluride (for example, or ZnTe), and lanthanidemetal telluride (for example, LaTe, CeTe, PrTe, NdTe, PmTe, EuTe, GdTe,TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, or LuTe).

[Emission Layer in Interlayer 130]

When the light-emitting device 10 is a full-color light-emitting device,the emission layer may be patterned into a red emission layer, a greenemission layer, and/or a blue emission layer, according to a subpixel.In embodiments, the emission layer may have a stacked structure of twoor more layers of a red emission layer, a green emission layer, and ablue emission layer, in which the two or more layers contact each otheror are separated from each other to emit white light. In embodiments,the emission layer may include two or more materials of a redlight-emitting material, a green light-emitting material, and a bluelight-emitting material, in which the two or more materials are mixedwith each other in a single layer to emit white light.

The emission layer may include a host and a dopant. The dopant mayinclude a phosphorescent dopant, a fluorescent dopant, or anycombination thereof.

The amount of the dopant in the emission layer may be in a range ofabout 0.01 to about 15 parts by weight based on 100 parts by weight ofthe host.

In embodiments, the emission layer may include a quantum dot.

The emission layer may include a delayed fluorescent material. Thedelayed fluorescent material may act as a host or a dopant in theemission layer.

A thickness of the emission layer may be in a range of about 100 Å toabout 1,000 Å. For example, the thickness of the emission layer may bein a range of about 200 Å to about 600 Å. When the thickness of theemission layer is within this range, excellent light-emissioncharacteristics may be obtained without a substantial increase indriving voltage.

[Host]

The host may include a compound represented by Formula 301 below:

[Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21)  [Formula 301]

In Formula 301,

Ar₃₀₁ and L₃₀₁ may each independently be a C₃-C₆₀ carbocyclic groupunsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least oneR_(10a),

xb11 may be 1,2, or 3,

xb1 may be an integer from 0 to 5,

R₃₀₁ may be hydrogen, deuterium, —F, —Cl, —Br, —I, hydroxyl group, acyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted orsubstituted with at least one R_(10a), a C₂-C₆₀ alkenyl groupunsubstituted or substituted with at least one R_(10a), a C₂-C₆₀alkynylgroup unsubstituted or substituted with at least one R_(10a), aC₁-C₆₀alkoxy group unsubstituted or substituted with at least oneR_(10a), a C₃-C₆₀ carbocyclic group unsubstituted or substituted with atleast one R_(10a), a C₁-C₆₀ heterocyclic group unsubstituted orsubstituted with at least one R_(10a), —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃),—N(Q₃₀₁)(Q₃₀₂), —B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), or—P(═O)(Q₃₀₁)(Q₃₀₂),

xb21 may be an integer from 1 to 5, and

Q₃₀₁ to Q₃₀₃ may be the same as described in connection with Q₁.

In embodiments, when xb11 in Formula 301 is 2 or more, two or more ofAr₃₀₁(s) may be linked to each other via a single bond.

In an embodiment, the host may include a compound represented by Formula301-1, a compound represented by Formula 301-2, or any combinationembodiment:

In Formulae 301-1 and 301-2,

ring A₃₀₁ to ring A₃₀₄ may each independently be a C₃-C₃₀ carbocyclicgroup unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least oneR_(10a),

X₃₀₁ may be O, S, N-[(L₃₀₄)_(xb4)-R₃₀₄], C(R₃₀₄)(R₃₀₅), orSi(R₃₀₄)(R₃₀₅),

xb22 and xb23 may each independently be 0, 1, or 2,

L₃₀₁, xb1, and R₃₀₁ are the same as described in the specification,

L₃₀₂ to L₃₀₄ may each independently be the same as described inconnection with L₃₀₁,

xb2 to xb4 may each independently be the same as described in connectionwith xb1, and

R₃₀₂ to R₃₀₅ and R₃₁₁ to R₃₁₄ may be the same as described in connectionwith R₃₀₁.

In embodiments, the host may include an alkaline earth metal complex. Inan embodiment, the host may be a Be complex (for example, Compound H55),a Mg complex, a Zn complex, or any combination thereof.

In an embodiment, the host may include one of Compounds H1 to H124,9,10-di(2-naphthyl)anthracene (ADN),2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN),9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN),4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene(mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), or any combinationthereof, but embodiments of the disclosure are not limited thereto:

[Phosphorescent Dopant]

The phosphorescent dopant may include at least one transition metal as acentral metal.

The phosphorescent dopant may include a monodentate ligand, a bidentateligand, a tridentate ligand, a tetradentate ligand, a pentadentateligand, a hexadentate ligand, or any combination thereof.

The phosphorescent dopant may be electrically neutral.

In embodiments, the phosphorescent dopant may include an organometalliccompound represented by Formula 401:

In Formulae 401 and 402,

M may be transition metal (for example, iridium (Ir), platinum (Pt),palladium (Pd), osmium (Os), titanium (Ti), gold (Au)hafnium (Hf),europium (Eu), terbium (Tb), rhodium (Rh), rhenium (Re), or thulium(Tm)),

L₄₀₁ may be a ligand represented by Formula 402, and xc1 may be 1,2, or3, wherein, when xc1 is 2 or more, two or more of L₄₀₁(s) may beidentical to or different from each other,

L₄₀₂ may be an organic ligand, and xc2 may be 0, 1, 2, 3, or 4, wherein,when xc2 is 2 or more, two or more of L₄₀₂(s) may be identical to ordifferent from each other,

X₄₀₁ and X₄₀₂ may each independently be nitrogen or carbon,

ring A₄₀₁ and ring A₄₀₂ may each independently be a C₃-C₆₀ carbocyclicgroup or a C₁-C₆₀ heterocyclic group,

T₄₀₁ may be a single bond, —O—, —S—, —C(═O)—, —N(Q₄₁₁)-,—C(Q₄₁₁)(Q₄₁₂)-, —C(Q₄₁₁)=C(Q₄₁₂)-, —C(Q₄₁₁)=, or ═C(Q₄₁₁)=,

X₄₀₃ and X₄₀₄ may each independently be a chemical bond (for example, acovalent bond or a coordinate bond), O, S, N(Q₄₁₃), B(Q₄₁₃), P(Q₄₁₃),C(Q₄₁₃)(Q₄₁₄), or Si(Q₄₁₃)(Q₄₁₄),

Q₄₁₁ to Q₄₁₄ may be the same as described in connection with Q₁,

R₄₀₁ and R₄₀₂ may each independently be hydrogen, deuterium, —F, —Cl,—Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₂₀ alkylgroup unsubstituted or substituted with at least one R_(10a), a C₁-C₂₀alkoxy group unsubstituted or substituted with at least one R_(10a), aC₃-C₆₀ carbocyclic group unsubstituted or substituted with at least oneR_(10a), a C₁-C₆₀ heterocyclic group unsubstituted or substituted withat least one R_(10a), —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂),—B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), or —P(═O)(Q₄₀₁)(Q₄O₂),

Q₄₀₁ to Q₄₀₃ may be the same as described in connection with Q₁,

xc11 and xc12 may each independently be an integer from 0 to 10, and

* and *′ in Formula 402 each indicate a binding site to M in Formula401.

In embodiments, in Formula 402, i) X₄₀₁ may be nitrogen, and X₄₀₂ may becarbon, or ii) each of X₄₀₁ and X₄₀₂ may be nitrogen.

In embodiments, when xc1 in Formula 402 is 2 or more, two ring A₄₀₁(s)in two or more L₄₀₁(s) may optionally be linked to each other via T₄₀₂,which is a linking group, or two ring A₄₀₂(S) in two or more L₄₀₁(s) mayoptionally be linked to each other via T₄₀₃, which is a linking group(see Compounds PD1 to PD4 and PD7). T₄₀₂ and T₄₀₃ may be the same asdescribed in connection with T₄₀₁.

L₄₀₂ in Formula 401 may be an organic ligand. In embodiments, L₄₀₂ maybe a halogen group, a diketone group (for example, an acetylacetonategroup), a carboxylic acid group (for example, a picolinate group),—C(═O), an isonitrile group, a —CN group, a phosphorus group (forexample, a phosphine group or a phosphite group), or any combinationthereof.

The phosphorescent dopant may include, for example, one of Compounds PD1to PD25 or any combination thereof:

[Fluorescent Dopant]

The fluorescent dopant may include an amine group-containing compound, astyryl group-containing compound, or any combination thereof.

In embodiments, the fluorescent dopant may include a compoundrepresented by Formula 501:

In Formula 501,

Ar₅₀₁, L₅₀₁ to L₅₀₃, R₅₀₁, and R₅₀₂ may each independently be a C₃-C₃₀carbocyclic group unsubstituted or substituted with at least one R_(10a)or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with atleast one R_(10a),

xd1 to xd3 may each independently be 0, 1, 2, or 3, and

xd4 may be 1, 2, 3, 4, 5, or 6.

In embodiments, Ar₅₀₁ in Formula 501 may be a condensed cyclic group(for example, an anthracene group, a chrysene group, or a pyrene group)in which three or more monocyclic groups are condensed with each other.

In embodiments, xd4 in Formula 501 may be 2.

In an embodiment, the fluorescent dopant may include one of CompoundsFD1 to FD36, DPVBi, DPAVBi, or any combination thereof:

[Delayed Fluorescent Material]

The emission layer may include a delayed fluorescent material.

The delayed fluorescent material used herein may be selected from anycompound that is capable of emitting delayed fluorescent light based ona delayed fluorescence emission mechanism.

The delayed fluorescent material included in the emission layer may actas a host or a dopant depending on the type of other materials includedin the emission layer.

In an embodiment, a difference between a triplet energy level (eV) ofthe delayed fluorescent material and a singlet energy level (eV) of thedelayed fluorescent material may be in a range of about 0 eV to about0.5 eV. When the difference between the triplet energy level (eV) of thedelayed fluorescent material and the singlet energy level (eV) of thedelayed fluorescent material satisfies the above-described range,up-conversion from a triplet state to a singlet state of the delayedfluorescent materials may effectively occur, and thus, the lightemission efficiency of the light-emitting device 10 may be improved.

In an embodiment, the delayed fluorescent material may include i) amaterial that includes at least one electron donor (for example, a πelectron-rich C₃-C₆₀ cyclic group, such as a carbazole group) and atleast one electron acceptor (for example, a sulfoxide group, a cyanogroup, or a π-electron-deficient nitrogen-containing C₁-C₆₀ cyclicgroup), ii) a material including a C₈-C₆₀ polycyclic group in which twoor more cyclic groups share boron (B) and are condensed with each other.

The delayed fluorescent material may include at least one of CompoundsDF1 to DF9:

[Quantum Dot]

The emission layer may include a quantum dot.

The quantum dot used herein refers to a crystal of a semiconductorcompound, and may include any material that is capable of emitting lightof various emission wavelengths depending on a size of the crystal.

A diameter of the quantum dot may be, for example, in a range of about 1nm to about 10 nm.

The quantum dot may be synthesized by a wet chemical process, anorganometallic chemical vapor deposition process, a molecular beamepitaxy process, or a process that is similar to these processes.

The wet chemical process refers to a method in which a solvent and aprecursor material are mixed, and a quantum dot particle crystal isgrown. When the crystal grows, the organic solvent acts as a dispersantnaturally coordinated on the surface of the quantum dot crystal andcontrols the growth of the crystal. Accordingly, by using a process thatis easily performed at low costs compared to a vapor deposition process,such as a metal organic chemical vapor deposition (MOCVD) process and amolecular beam epitaxy (MBE) process, the growth of quantum dotparticles may be controlled.

The quantum dot may include Groups III-VI semiconductor compound, GroupsII-VI semiconductor compound, Groups III-V semiconductor compound, GroupI-III-VI semiconductor compound, Groups IV-VI semiconductor compound,Group IV element or compound, or any combination thereof.

Examples of the Groups III-VI semiconductor compound may include: abinary compound, such as In₂S₃; a ternary compound, such as AgInS,AgInS₂, CuInS, or CuInS₂; or any combination thereof.

Examples of the Groups II-VI semiconductor compound may include: abinary compound, such as CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe,HgTe, MgSe, or MgS; a ternary compound, such as CdSeS, CdSeTe, CdSTe,ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe,CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, or MgZnS; aquaternary compound, such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS,CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, or HgZnSTe; or any combinationthereof.

Examples of the Groups III-V semiconductor compound may include: abinary compound, such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb,InN, InP, InAs, or InSb; a ternary compound, such as GaNP, GaNAs, GaNSb,GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP,InNAs, InNSb, InPAs, InPSb, or GaAlNP; a quaternary compound, such asGaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs,GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, or InAlPSb; or anycombination thereof. The Groups III-V semiconductor compound may furtherinclude a Group II element. Examples of the Groups III-V semiconductorcompound further including a Group II element may include InZnP,InGaZnP, or InAlZnP.

Examples of the Groups III-VI semiconductor compound may include: abinary compound, such as GaS, GaSe, Ga₂Se₃, GaTe, InS, InSe, In₂Se₃, orInTe; a ternary compound, such as InGaSs, or InGaSes; or any combinationthereof.

Examples of the Group I-III-VI semiconductor compound may include: aternary compound, such as AgInS, AgInS₂, CuInS, CuInS₂, CuGaO₂, AgGaO₂,or AgAlO₂; or any combination thereof.

Examples of the Group IV-VI semiconductor compound may include: a binarycompound, such as SnS, SnSe, SnTe, PbS, PbSe, or PbTe; a ternarycompound, such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS,SnPbSe, or SnPbTe; a quaternary compound, such as SnPbSSe, SnPbSeTe, orSnPbSTe; or any combination thereof.

In an embodiment, the Group IV element or compound may include: a singleelement compound, such as Si or Ge; a binary compound, such as SiC orSiGe; or any combination thereof.

Each element included in the multi-element compound such as the binarycompound, ternary compound, and quaternary compound may be present in aparticle at a uniform concentration or a non-uniform concentration.

The quantum dot may have a single structure having a uniformconcentration of each element included in the corresponding quantum dotor a dual structure of a core-shell. In an embodiment, the materialincluded in the core may be different from the material included in theshell.

The shell of the quantum dot may function as a protective layer formaintaining semiconductor characteristics by preventing chemicaldegeneration of the core and/or may function as a charging layer forimparting electrophoretic characteristics to the quantum dot. The shellmay be a single layer or a multilayer. An interface between the core andthe shell may have a concentration gradient in which the concentrationof elements existing in the shell decreases toward the center.

Examples of the shell of the quantum dot are a metal or non-metal oxide,a semiconductor compound, or any combination thereof. Examples of theoxide of metal or non-metal may include: a binary compound, such asSiO₂, Al₂O₃, TiO₂, ZnO, MnO, Mn₂O₃, Mn₃O₄, CuO, FeO, Fe₂O₃, Fe₃O₄, CoO,Co₃O₄, or NiO; a ternary compound, such as MgAl₂O₄, CoFe₂O₄, NiFe₂O₄, orCoMn₂O₄; or any combination thereof. Examples of the semiconductorcompound may include, as described herein, Groups III-VI semiconductorcompound, Groups II-VI semiconductor compound, Groups III-Vsemiconductor compound, Groups I-III-VI semiconductor compound, GroupsIV-VI semiconductor compound, or any combination thereof. In anembodiment, the semiconductor compound may include CdS, CdSe, CdTe, ZnS,ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP,InGaP, InSb, AlAs, AlP, AlSb, or any combination thereof.

A full width at half maximum (FWFIM) of an emission wavelength spectrumof the quantum dot may be equal to or less than about 45 nm. Forexample, the FWFIM of an emission wavelength spectrum of the quantum dotmay be equal to or less than about 40 nm. For example, the FWFIM of anemission wavelength spectrum of the quantum dot may be equal to or lessthan about 30 nm. When the FWHM of the emission wavelength spectrum ofthe quantum dot is within this range, color purity or color reproductionmay be improved. Light emitted through the quantum dot may be irradiatedomnidirectionally. Accordingly, a wide viewing angle may be increased.

The quantum dot may be a spherical, a pyramidal, a multi-arm, or a cubicnanoparticle, a nanotube, a nanowire, a nanofiber, or a nanoplateparticle.

By adjusting the size of the quantum dot, the energy band gap may alsobe adjusted, thereby obtaining light of various wavelengths in a quantumdot emission layer. Therefore, by using quantum dots of different sizes,a light-emitting device that emits light of various wavelengths may beimplemented. For example, the size of the quantum dot may be selected toemit red, green and/or blue light. The size of the quantum dot may beadjusted such that light of various colors are combined to emit whitelight.

[Electron Transport Region in Interlayer 130]

The electron transport region may have: i) a single-layered structureconsisting of a single layer consisting of a single material, ii) asingle-layered structure consisting of a single layer includingdifferent materials, or iii) a multi-layered structure includingmultiple layers including different materials.

The electron transport region may include a hole blocking layer, anelectron transport layer, an electron injection layer, or anycombination thereof.

In an embodiment, the electron transport region may have an electrontransport layer/electron injection layer structure or a hole blockinglayer/electron transport layer/electron injection layer structure,wherein, in each structure, layers are stacked sequentially from theemission layer.

The electron transport region (for example, the hole blocking layer orthe electron transport layer in the electron transport region) mayinclude a metal-free compound including at least oneπ-electron-deficient nitrogen-containing C₁-C₆₀ cyclic group.

In an embodiment, the electron transport region may include a compoundrepresented by Formula 601 below:

[Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21)  [Formula 601]

In Formula 601,

Ar₆₀₁ and L₆₀₁ may each independently be a C₃-C₆₀ carbocyclic groupunsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least oneR_(10a),

xe11 may be 1,2, or 3,

xe1 may be 0, 1, 2, 3, 4, or 5,

R₆₀₁ may be a C₃-C₆₀ carbocyclic group unsubstituted or substituted withat least one R_(10a), a C₁-C₆₀ heterocyclic group unsubstituted orsubstituted with at least one R_(10a), —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃),—C(═O)(Q₆₀₁), —S(═O)₂(Q₆₀₁), or —P(═O)(Q₆₀₁)(Q₆₀₂),

Q₆₀₁ to Q₆O₃ may be the same as described in connection with Q₁,

xe21 may be 1, 2, 3, 4, or 5, and

at least one of Ar₆₀₁, L₆₀₁, and R₆₀₁ may each independently be aπ-electron-deficient nitrogen-containing C₁-C₆₀ cyclic groupunsubstituted or substituted with at least one R_(10a).

In embodiments, when xe11 in Formula 601 is 2 or more, two or more ofAr₆₀₁(s) may be linked to each other via a single bond.

In an embodiment, Ar₆₀₁ in Formula 601 may be a substituted orunsubstituted anthracene group.

In an embodiment, the electron transport region may include a compoundrepresented by Formula 601-1:

In Formula 601-1,

X₆₁₄ may be N or C(R_(6u)), X₆₁₅ may be N or C(R₆₁₅), X₆₁₆ may be N orC(R₆₁₆), and at least one of X₆₁₄ to X₆₁₆ may be N,

L₆₁₁ to L₆₁₃ may be the same as described in connection with L₆₀₁,

xe611 to xe613 may be the same as described in connection with xe1,

R₆₁₁ to R₆₁₃ may be the same as described in connection with R₆₀₁, and

R₆₁₄ to R₆₁₆ may each independently be hydrogen, deuterium, —F, —Cl,—Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₂₀ alkylgroup, a C₁-C₂₀ alkoxy group, a C₃-C₆₀ carbocyclic group unsubstitutedor substituted with at least one R_(10a), or a C₁-C₆₀ heterocyclic groupunsubstituted or substituted with at least one R_(10a).

In an embodiment, xe1 and xe611 to xe613 in Formula 601 and 601-1 mayeach independently be 0, 1, or 2.

The electron transport region may include one of Compounds ET1 to ET45,2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP),4,7-diphenyl-1,10-phenanthroline (Bphen), Alq₃, BAlq, TAZ, NTAZ, or anycombination thereof:

A thickness of the electron transport region may be in a range of about160 Å to about 5,000 Å. For example, the thickness of the electrontransport region may be in a range of about 100 Å to about 4,000 Å. Whenthe electron transport region includes the hole blocking layer, theelectron transport layer, or any combination thereof, a thickness of thehole blocking layer may be in a range of about 20 Å to about 1,000 Å,and a thickness of the electron transport layer may be in a range ofabout 100 Å to about 1,000 Å. For example, the thickness of the holeblocking layer may be in a range of about 30 Å to about 300 Å. Forexample, the thickness of the electron transport layer may be in a rangeof about 150 Å to about 500 Å. When a thickness of the hole blockinglayer and/or the electron transport layer is within these ranges,satisfactory electron transport characteristics may be obtained withouta substantial increase in a driving voltage.

The electron transport region (for example, the electron transport layerin the electron transport region) may further include, in addition tothe materials described above, a metal-containing material.

The metal-containing material may include an alkali metal complex, analkaline earth-metal complex, or any combination thereof. A metal ion ofthe alkali metal complex may be a Li ion, a Na ion, a K ion, a Rb ion,or a Cs ion, and a metal ion of the alkaline earth-metal complex may bea Be ion, a Mg ion, a Ca ion, a Sr ion, or a Ba ion. A ligandcoordinated with the metal ion of the alkali metal complex or thealkaline earth-metal complex may each independently be a hydroxyquinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, a hydroxyacridine, a hydroxy phenanthridine, a hydroxy phenyloxazole, a hydroxyphenylthiazole, a hydroxy diphenyloxadiazole, a hydroxydiphenylthiadiazole, a hydroxy phenylpyridine, a hydroxyphenylbenzimidazole, a hydroxy phenylbenzothiazole, a bipyridine, aphenanthroline, a cyclopentadiene, or any combination thereof.

In an embodiment, the metal-containing material may include a Licomplex. The Li complex may include, for example, Compound ET-D1 (LiQ)or ET-D2:

The electron transport region may include an electron injection layerthat facilitates the injection of electrons from the second electrode150. The electron injection layer may be in direct contact with thesecond electrode 150.

The electron injection layer may have: i) a single-layered structureconsisting of a single layer consisting of a single material, ii) asingle-layered structure consisting of a single layer includingdifferent materials, or iii) a multi-layered structure includingmultiple layers including different materials.

The electron injection layer may include an alkali metal, an alkalineearth metal, a rare earth metal, an alkali metal-containing compound, analkaline earth metal-containing compound, a rare earth metal-containingcompound, an alkali metal complex, an alkaline earth-metal complex, arare earth metal complex, or any combination thereof.

The alkali metal may include Li, Na, K, Rb, Cs, or any combinationthereof. The alkaline earth metal may include Mg, Ca, Sr, Ba, or anycombination thereof. The rare earth metal may include Sc, Y, Ce, Tb, Yb,Gd, or any combination thereof.

The alkali metal-containing compound, the alkaline earthmetal-containing compound, and the rare earth metal-containing compoundmay be oxides and halides (for example, fluorides, chlorides, bromides,or iodides) of the alkali metal, the alkaline earth metal, and the rareearth metal, telluride, or any combination thereof.

The alkali metal-containing compound may be alkali metal oxides, such asLi₂O, Cs₂O, or K₂O, and alkali metal halides, such as LiF, NaF, CsF, KF,LiI, NaI, CsI, or KI, or any combination thereof. The alkaline earthmetal-containing compound may include an alkaline earth metal compound,such as BaO, SrO, CaO, Ba_(x)Sr_((1-x))O (x is a real number thatsatisfies the condition of 0<x<1), or Ba_(x)Ca_((1-x))O (x is a realnumber that satisfies the condition of 0<x<1). The rare earthmetal-containing compound may include YbF₃, ScF₃, Sc₂O₃, Y₂O₃, Ce₂O₃,GdF₃, TbF₃, YbI₃, ScI₃, TbI₃, or any combination thereof. In anembodiment, the rare earth metal-containing compound may includelanthanide metal telluride. Examples of the lanthanide metal telluridemay include LaTe, CeTe, PrTe, NdTe, PmTe, SmTe, EuTe, GdTe, TbTe, DyTe,FloTe, ErTe, TmTe, YbTe, LuTe, La₂Te₃, Ce₂Te₃, Pr₂Te₃, Nd₂Te₃, Pm₂Te₃,Sm₂Te₃, Eu₂Te₃, Gd₂Te₃, Tb₂Te₃, Dy₂Te₃, Ho₂Te₃, Er₂Te₃, Tm₂Te₃, Yb₂Te₃,and Lu₂Te₃.

The alkali metal complex, the alkaline earth-metal complex, and the rareearth metal complex may include i) one of ions of the alkali metal, thealkaline earth metal, and the rare earth metal and ii) as a ligandlinked to the metal ion, for example, a hydroxy quinoline, a hydroxyisoquinoline, a hydroxy benzoquinoline, a hydroxy acridine, a hydroxyphenanthridine, a hydroxy phenyloxazole, a hydroxy phenylthiazole, ahydroxy diphenyloxadiazole, a hydroxy diphenylthiadiazole, a hydroxyphenylpyridine, a hydroxy phenylbenzimidazole, a hydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, a cyclopentadiene,or any combination thereof.

The electron injection layer may consist of an alkali metal, an alkalineearth metal, a rare earth metal, an alkali metal-containing compound, analkaline earth metal-containing compound, a rare earth metal-containingcompound, an alkali metal complex, an alkaline earth-metal complex, arare earth metal complex, or any combination thereof, or may furtherinclude an organic material (for example, a compound represented byFormula 601).

In an embodiment, the electron injection layer may consist of i) analkali metal-containing compound (for example, an alkali metal halide),or ii) a) an alkali metal-containing compound (for example, an alkalimetal halide); and b) alkali metal, alkaline earth metal, rare earthmetal, or any combination thereof. In an embodiment, the electroninjection layer may be a KI:Yb co-deposited layer or a RbI:Ybco-deposited layer.

When the electron injection layer further includes an organic material,an alkali metal, an alkaline earth metal, a rare earth metal, an alkalimetal-containing compound, an alkaline earth metal-containing compound,a rare earth metal-containing compound, an alkali metal complex, analkaline earth-metal complex, a rare earth metal complex, or anycombination thereof may be homogeneously or non-homogeneously dispersedin a matrix including the organic material.

A thickness of the electron injection layer may be in a range of about 1Å to about 100 Å. For example, the thickness of the electron injectionlayer may be in a range of about 3 Å to about 90 Å. When the thicknessof the electron injection layer is within the range described above, theelectron injection layer may have satisfactory electron injectioncharacteristics without a substantial increase in driving voltage.

[Second Electrode 150]

The second electrode 150 may be located on the interlayer 130 havingsuch a structure. The second electrode 150 may be a cathode, which is anelectron injection electrode, and as a material for forming the secondelectrode 150, a metal, an alloy, an electrically conductive compound,or any combination thereof, each having a low work function, may beused.

The second electrode 150 may include at least one selected from lithium(Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium(Al—Li), calcium (Ca), magnesium-indium (Mg-ln), magnesium-silver(Mg—Ag), ytterbium (Yb), silver-ytterbium (Ag—Yb), ITO, IZO, or anycombination thereof. The second electrode 150 may be a transmissiveelectrode, a semi-transmissive electrode, or a reflective electrode.

The second electrode 150 may have a single-layered structure or amulti-layered structure including two or more layers.

[Capping Layer]

A first capping layer and a second capping layer may be disposed outsidethe second electrode 150. In an embodiment, the light-emitting device 10may have a structure in which the first electrode 110, the interlayer130, the second electrode 150, the first capping layer, and the secondcapping layer are sequentially stacked.

Light generated in the emission layer of the interlayer 130 of thelight-emitting device 10 may be extracted toward the outside through thesecond electrode 150, which is a semi-transmissive electrode or atransmissive electrode, the first capping layer, and the second cappinglayer.

The first capping layer and the second capping layer may increaseexternal light emission efficiency according to the principle ofconstructive interference. When a refractive index and a thickness ofthe first capping layer and the second capping layer are within therange, light extraction efficiency of the light-emitting device 10 isincreased, and thus light emission efficiency of the light-emittingdevice 10 may be improved.

The first capping layer and the second capping layer may eachindependently be an organic capping layer including an organic material.In an embodiment, the first capping layer and the second capping layermay be organic layers each consisting of organic materials.

A compound represented by Formula 1 and a compound represented byFormula 2, as the organic materials included in the first capping layerand the second capping layer, respectively, are the same as describedabove.

[Electronic Apparatus]

The light-emitting device may be included in various electronicapparatuses. In an embodiment, the electronic apparatus including thelight-emitting device may be a light-emitting apparatus, anauthentication apparatus, or the like.

The electronic apparatus (for example, light-emitting apparatus) mayfurther include, in addition to the light-emitting device, i) a colorfilter, ii) a color conversion layer, or iii) a color filter and a colorconversion layer. The color filter and/or the color conversion layer maybe located in at least one traveling direction of light emitted from thelight-emitting device. In an embodiment, light emitted from thelight-emitting device may be blue light or white light. Thelight-emitting device may be the same as described above. In anembodiment, the color conversion layer may include a quantum dot. Thequantum dot may be, for example, a quantum dot as described herein.

The electronic apparatus may include a first substrate. The firstsubstrate may include subpixels, the color filter may include colorfilter areas corresponding to the subpixels, respectively, and the colorconversion layer may include a plurality of color conversion areascorresponding to the subpixels, respectively.

A pixel-defining film may be between the subpixels to define each of thesubpixels.

The color filter may further include color filter areas and alight-blocking pattern between the color filter areas, and the colorconversion layer may further include color conversion areas and alight-blocking pattern between the color conversion areas.

The color filter areas (or the color conversion areas) may include afirst area emitting first color light, a second area emitting secondcolor light, and/or a third area emitting third color light, and thefirst color light, the second color light, and/or the third color lightmay have different maximum emission wavelengths from one another. In anembodiment, the first color light may be red light, the second colorlight may be green light, and the third color light may be blue light.In an embodiment, the color filter areas (or the color conversion areas)may include a quantum dot. For example, first area may include a redquantum dot, the second area may include a green quantum dot, and thethird area may not include a quantum dot. The quantum dot is the same asdescribed in the specification. Each of the first area, the second area,and/or the third area may further include a scatterer.

In an embodiment, the light-emitting device may emit first light, thefirst area may absorb the first light to emit first first-color light,the second area may absorb the first light to emit second first-colorlight, and the third area may absorb the first light to emit thirdfirst-color light. In this regard, the first first-color light, thesecond first-color light, and the third first-color light may havedifferent maximum emission wavelengths from one another. For example,first light may be blue light, the first first-color light may be redlight, the second first-color light may be green light, and the thirdfirst-color light may be blue light.

The electronic apparatus may further include a thin-film transistor inaddition to the light-emitting device as described above. The thin-filmtransistor may include a source electrode, a drain electrode, and anactive layer, wherein any one of the source electrode and the drainelectrode may be electrically connected to any one of the firstelectrode and the second electrode of the light-emitting device.

The thin-film transistor may further include a gate electrode, a gateinsulating film, or the like.

The activation layer may include crystalline silicon, amorphous silicon,organic semiconductor, oxide semiconductor, or the like.

The electronic apparatus may further include a sealing portion forsealing the light-emitting device. The sealing portion may be disposedbetween the color filter and/or the color conversion layer and thelight-emitting device. The sealing portion allows light from thelight-emitting device to be extracted to the outside, whilesimultaneously preventing ambient air and moisture from penetrating intothe light-emitting device. The sealing portion may be a sealingsubstrate including a transparent glass substrate or a plasticsubstrate. The sealing portion may be a thin film encapsulation layerincluding at least one layer of an organic layer and/or an inorganiclayer. When the sealing portion is a thin film encapsulation layer, theelectronic apparatus may be flexible.

On the sealing portion, in addition to the color filter and/or the colorconversion layer, various functional layers may be further disposedaccording to the use of the electronic apparatus. The functional layersmay include a touch screen layer, a polarizing layer, and the like. Thetouch screen layer may be a pressure-sensitive touch screen layer, acapacitive touch screen layer, or an infrared touch screen layer. Theauthentication apparatus may be, for example, a biometric authenticationapparatus for authenticating an individual by using biometricinformation of a biometric body (for example, a finger tip, a pupil, orthe like).

The authentication apparatus may further include, in addition to thelight-emitting device, a biometric information collector.

The electronic apparatus may be applied to various displays, lightsources, lighting, personal computers (for example, a mobile personalcomputer), mobile phones, digital cameras, electronic organizers,electronic dictionaries, electronic game machines, medical instruments(for example, electronic thermometers, sphygmomanometers, blood glucosemeters, pulse measurement devices, pulse wave measurement devices,electrocardiogram displays, ultrasonic diagnostic devices, or endoscopedisplays), fish finders, various measuring instruments, meters (forexample, meters for a vehicle, an aircraft, and a vessel), projectors,and the like.

[Description of FIGS. 2 and 3]

FIG. 2 is a schematic cross-sectional view of a light-emitting apparatusaccording to an embodiment.

The light-emitting apparatus of FIG. 2 includes a substrate 100, athin-film transistor (TFT), a light-emitting device, and anencapsulation portion 300 that seals the light-emitting device.

The substrate 100 may be a flexible substrate, a glass substrate, or ametal substrate. A buffer layer 210 may be located on the substrate 100.The buffer layer 210 prevents the penetration of impurities through thesubstrate 100 and may provide a flat surface on the substrate 100.

A TFT may be located on the buffer layer 210. The TFT may include anactive layer 220, a gate electrode 240, a source electrode 260, and adrain electrode 270.

The active layer 220 may include an inorganic semiconductor such assilicon or polysilicon, an organic semiconductor, or an oxidesemiconductor, and may include a source region, a drain region, and achannel region.

A gate insulating film 230 for insulating the active layer 220 from thegate electrode 240 may be located on the active layer 220, and the gateelectrode 240 may be located on the gate insulating film 230.

An interlayer insulating film 250 may be located on the gate electrode240. The interlayer insulating film 250 is located between the gateelectrode 240 and the source electrode 260 to insulate the gateelectrode 240 from the source electrode 260 and between the gateelectrode 240 and the drain electrode 270 to insulate the gate electrode240 from the drain electrode 270.

The source electrode 260 and the drain electrode 270 may be located onthe interlayer insulating film 250. The interlayer insulating film 250and the gate insulating film 230 may be formed to expose the sourceregion and the drain region of the active layer 220, and the sourceelectrode 260 and the drain electrode 270 may be disposed to contact theexposed portions of the source region and the drain region of the activelayer 220.

The TFT may be electrically connected to a light-emitting device todrive the light-emitting device, and is covered by a passivation layer280. The passivation layer 280 may include an inorganic insulating film,an organic insulating film, or a combination thereof. A light-emittingdevice is provided on the passivation layer 280. The light-emittingdevice includes the first electrode 110, the interlayer 130, and thesecond electrode 150.

The first electrode 110 may be disposed on the passivation layer 280.The passivation layer 280 does not completely cover the drain electrode270 and may expose a region of the drain electrode 270, and the firstelectrode 110 may be connected to the exposed region of the drainelectrode 270.

A pixel defining layer 290 including an insulating material may belocated on the first electrode 110. The pixel defining layer 290 mayexpose a region of the first electrode 110, and the interlayer 130 maybe formed in the exposed region of the first electrode 110. The pixeldefining layer 290 may be a polyimide or polyacryl-based organic film.Although not shown in FIG. 2, at least some layers of the interlayer 130may extend beyond the upper portion of the pixel defining layer 290 andmay thus be disposed in the form of a common layer.

The second electrode 150 may be disposed on the interlayer 130, and acapping layer 170 may be additionally formed on the second electrode150. The capping layer 170 may be formed to cover the second electrode150. The capping layer 170 may include the first capping layer and thesecond capping layer as described above.

The encapsulation portion 300 may be located on the capping layer 170.The encapsulation portion 300 may be located on a light-emitting deviceand protects the light-emitting device from moisture or oxygen. Theencapsulation portion 300 may include: an inorganic film includingsilicon nitride (SiNx), silicon oxide (SiOx), indium tin oxide, indiumzinc oxide, or a combination thereof; an organic film includingpolyethylene terephthalate, polyethylene naphthalate, polycarbonate,polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate,hexamethyldisiloxane, an acrylic resin (for example, polymethylmethacrylate or polyacrylic acid), an epoxy-based resin (for example,aliphatic glycidyl ether (AGE), or a combination thereof; or acombination of an inorganic film and an organic film.

FIG. 3 is a schematic cross-sectional view showing a light-emittingapparatus according to an embodiment of the disclosure.

The light-emitting apparatus of FIG. 3 is the same as the light-emittingapparatus of FIG. 2, except that a light-blocking pattern 500 and afunctional region 400 are additionally disposed on the encapsulationportion 300. The functional region 400 may be i) a color filter area,ii) a color conversion area, or iii) a combination of the color filterarea and the color conversion area. In an embodiment, the light-emittingdevice included in the light-emitting apparatus of FIG. 3 may be atandem light-emitting device.

[Preparation Method]

Layers constituting the hole transport region, an emission layer, andlayers constituting the electron transport region may be formed in acertain region by using one or more suitable methods selected fromvacuum deposition, spin coating, casting, Langmuir-Blodgett (LB)deposition, ink-jet printing, laser-printing, and laser-induced thermalimaging.

When layers constituting the hole transport region, an emission layer,and layers constituting the electron transport region are formed byvacuum deposition, the deposition may be performed at a depositiontemperature of about 100° C. to about 500° C., a vacuum degree of about10′⁸ torr to about 10′³ torr, and a deposition speed of about 0.01 Å/secto about 100 Å/sec by taking into account a material to be included in alayer to be formed and the structure of a layer to be formed.

Definition of Terms

The term “C₃-C₆₀ carbocyclic group” as used herein refers to a cyclicgroup that consists of carbon only and has three to sixty carbon atoms,and the term “C₁-C₆₀ heterocyclic group” as used herein refers to acyclic group that has one to sixty carbon atoms and further includes, inaddition to carbon, a heteroatom. The C₃-C₆₀ carbocyclic group and theC₁-C₆₀ heterocyclic group may each be a monocyclic group that consistsof one ring or a polycyclic group in which two or more rings arecondensed with each other. In an embodiment, the number of ring-formingatoms of the C₁-C₆₀ heterocyclic group may be from 3 to 61.

The term “cyclic group” as used herein includes the C₃-C₆₀ carbocyclicgroup and the C₁-C₆₀ heterocyclic group.

The term “π electron-rich C₃-C₆₀ cyclic group” as used herein refers toa cyclic group that has three to sixty carbon atoms and does not include*—N=*′ as a ring-forming moiety, and the term “π-electron-deficientnitrogen-containing C₁-C₆₀ cyclic group” as used herein refers to aheterocyclic group that has one to sixty carbon atoms and includes*—N=*′ as a ring-forming moiety.

For example,

the C₃-C₃₀ carbocyclic group may be i) a group T1 or ii) a condensedcyclic group in which two or more groups T1 are condensed with eachother (for example, a cyclopentadiene group, an adamantane group, anorbornane group, a benzene group, a pentalene group, a naphthalenegroup, an azulene group, an indacene group, acenaphthylene group, aphenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a perylene group, a pentaphene group, a heptalene group, anaphthacene group, a picene group, a hexacene group, a pentacene group,a rubicene group, a coronene group, an ovalene group, an indene group, afluorene group, a spiro-bifluorene group, a benzofluorene group, anindenophenanthrene group, or an indenoanthracene group),

the C₁-C₆₀ heterocyclic group may be i) a group T2, ii) a condensedcyclic group in which two or more groups T2 are condensed with eachother, or iii) a condensed cyclic group in which at least one groups T2and at least one group T1 are condensed with each other (for example, apyrrole group, a thiophene group, a furan group, an indole group, abenzoindole group, a naphthoindole group, an isoindole group, abenzoisoindole group, a naphthoisoindole group, a benzosilole group, abenzothiophene group, a benzofuran group, a carbazole group, adibenzosilole group, a dibenzothiophene group, a dibenzofuran group, anindenocarbazole group, an indolocarbazole group, a benzofurocarbazolegroup, a benzothienocarbazole group, a benzosilolocarbazole group, abenzoindolocarbazole group, a benzocarbazole group, a benzonaphthofurangroup, a benzonaphthothiophene group, a benzonaphthosilole group, abenzofurodibenzofuran group, a benzofurodibenzothiophene group, abenzothieno dibenzothiophene group, a pyrazole group, an imidazolegroup, a triazole group, an oxazole group, an isoxazole group, anoxadiazole group, a thiazole group, an isothiazole group, a thiadiazolegroup, a benzopyrazole group, a benzimidazole group, a benzoxazolegroup, a benzoisoxazole group, a benzothiazole group, a benzoisothiazolegroup, a pyridine group, a pyrimidine group, a pyrazine group, apyridazine group, a triazine group, a quinoline group, an isoquinolinegroup, a benzoquinoline group, a benzoisoquinoline group, a quinoxalinegroup, a benzoquinoxaline group, a quinazoline group, a benzoquinazolinegroup, a phenanthroline group, a cinnoline group, a phthalazine group, anaphthyridine group, an imidazopyridine group, an imidazopyrimidinegroup, an imidazotriazine group, an imidazopyrazine group, animidazopyridazine group, an azacarbazole group, an azafluorene group, anazadibenzosilole group, an azadibenzothiophene group, or anazadibenzofuran group),

the π electron-rich C₃-C₆₀ cyclic group may be i) a group T1, ii) acondensed cyclic group in which two or more groups T1 are condensed witheach other, iii) a group T3, iv) a condensed cyclic group in which twoor more groups T3 are condensed with each other, or v) a condensedcyclic group in which at least one group T3 and at least one group T1are condensed with each other (for example, a C₃-C₆₀ carbocyclic group,a pyrrole group, a thiophene group, a furan group, an indole group, abenzoindole group, a naphthoindole group, an isoindole group, abenzoisoindole group, a naphthoisoindole group, a benzosilole group, abenzothiophene group, a benzofuran group, a carbazole group, adibenzosilole group, a dibenzothiophene group, a dibenzofuran group, anindenocarbazole group, an indolocarbazole group, a benzofurocarbazolegroup, a benzothienocarbazole group, a benzosilolocarbazole group, abenzoindolocarbazole group, a benzocarbazole group, a benzonaphthofurangroup, a benzonaphthothiophene group, a benzonaphthosilole group, abenzofurodibenzofuran group, a benzofurodibenzothiophene group, or abenzothienodibenzothiophene group),

the π-electron-deficient nitrogen-containing C₁-C₆₀ cyclic group may bei) a group T4, ii) a condensed cyclic group in which two or more groupsT4 are condensed with each other, iii) a condensed cyclic group in whichat least one group T4 and at least one group T1 are condensed with eachother, iv) a condensed cyclic group in which at least one group T4 andat least one group T3 are condensed with each other, or v) a condensedcyclic group in which at least one group T4, at least one group T1, andat least one group T3 are condensed with each other (for example, apyrazole group, an imidazole group, a triazole group, an oxazole group,an isoxazole group, an oxadiazole group, a thiazole group, anisothiazole group, a thiadiazole group, a benzopyrazole group, abenzimidazole group, a benzoxazole group, a benzoisoxazole group, abenzothiazole group, a benzoisothiazole group, a pyridine group, apyrimidine group, a pyrazine group, a pyridazine group, a triazinegroup, a quinoline group, an isoquinoline group, a benzoquinoline group,a benzoisoquinoline group, a quinoxaline group, a benzoquinoxalinegroup, a quinazoline group, a benzoquinazoline group, a phenanthrolinegroup, a cinnoline group, a phthalazine group, a naphthyridine group, animidazopyridine group, an imidazopyrimidine group, an imidazotriazinegroup, an imidazopyrazine group, an imidazopyridazine group, anazacarbazole group, an azafluorene group, an azadibenzosilole group, anazadibenzothiophene group, or an azadibenzofuran group),

the group T1 may be a cyclopropane group, a cyclobutane group, acyclopentane group, a cyclohexane group, a cycloheptane group, acyclooctane group, a cyclobutene group, a cyclopentene group, acyclopentadiene group, a cyclohexene group, a cyclohexadiene group, acycloheptene group, an adamantane group, a norbornane group (or, abicyclo[2.2.1]heptane group), a norbornene group, abicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, abicyclo[2.2.2]octane group, or a benzene group,

the group T2 may be a furan group, a thiophene group, a 1H-pyrrolegroup, a silole group, a borole group, a 2H-pyrrole group, a 3H-pyrrolegroup, an imidazole group, a pyrazole group, a triazole group, atetrazole group, an oxazole group, an isoxazole group, an oxadiazolegroup, a thiazole group, an isothiazole group, a thiadiazole group, anazasilole group, an azaborole group, a pyridine group, a pyrimidinegroup, a pyrazine group, a pyridazine group, a triazine group, or atetrazine group,

the group T3 may be a furan group, a thiophene group, a 1H-pyrrolegroup, a silole group, or a borole group, and

the group T4 may be a 2H-pyrrole group, a 3H-pyrrole group, an imidazolegroup, a pyrazole group, a triazole group, a tetrazole group, an oxazolegroup, an isoxazole group, an oxadiazole group, a thiazole group, anisothiazole group, a thiadiazole group, an azasilole group, an azaborolegroup, a pyridine group, a pyrimidine group, a pyrazine group, apyridazine group, a triazine group, or a tetrazine group.

The terms “the cyclic group,” “the C₃-C₆₀ carbocyclic group,” “theC₁-C₆₀ heterocyclic group,” “the π electron-rich C₃-C₆₀ cyclic group,”or “the π-electron-deficient nitrogen-containing C₁-C₆₀ cyclic group” asused herein refer to a group that is condensed with a cyclic group, amonovalent group, a polyvalent group (for example, a divalent group, atrivalent group, a tetravalent group, or the like), according to astructure of a formula described with corresponding terms. Inembodiments, “a benzene group” may be a benzo group, a phenyl group, aphenylene group, or the like, which may be easily understand by one ofordinary skill in the art according to a structure of a formulaincluding the “benzene group.”

In an embodiment, examples of the monovalent C₃-C₆₀ carbocyclic groupand the monovalent C₁-C₆₀ heterocyclic group may include a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, andexamples of the divalent C₃-C₆₀ carbocyclic group and the monovalentC₁-C₃₀ heterocyclic group may include a C₃-C₁₀ cycloalkylene group, aC₁-C₁₀ heterocycloalkylene group, a C₃-C₁₀ cycloalkenylene group, aC₁-C₁₀ heterocycloalkenylene group, a C₆-C₆₀ arylene group, a C₁-C₆₀heteroarylene group, a divalent non-aromatic condensed polycyclic group,and a substituted or unsubstituted divalent non-aromatic condensedheteropolycyclic group.

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear orbranched aliphatic hydrocarbon monovalent group having 1 to 60 carbonatoms, and examples thereof include a methyl group, an ethyl group, ann-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group,an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentylgroup, a neopentyl group, an isopentyl group, a sec-pentyl group, a3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexylgroup, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, anisoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octylgroup, an isooctyl group, a sec-octyl group, a tert-octyl group, ann-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group,an n-decyl group, an isodecyl group, a sec-decyl group, and a tert-decylgroup. The term “C₁-C₆₀ alkylene group” as used herein refers to adivalent group having the same structure as the C₁-C₆₀ alkyl group.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a monovalenthydrocarbon group having at least one carbon-carbon double bond in themiddle or at the terminus of a C₂-C₆₀ alkyl group, and examples thereofinclude an ethenyl group, a propenyl group, and a butenyl group. Theterm “C₂-C₆₀ alkenylene group” as used herein refers to a divalent grouphaving the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a monovalenthydrocarbon group having at least one carbon-carbon triple bond in themiddle or at the terminus of a C₂-C₆₀ alkyl group, and examples thereofinclude an ethynyl group and a propynyl group. The term “C₂-C₆₀alkynylene group” as used herein refers to a divalent group having thesame structure as the C₂-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalentgroup represented by —OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group),and examples thereof include a methoxy group, an ethoxy group, and anisopropyloxy group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalentsaturated hydrocarbon cyclic group having 3 to 10 carbon atoms, andexamples thereof include a cyclopropyl group, a cyclobutyl group, acyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cycloctylgroup, an adamantanyl group, a norbornanyl group (or abicyclo[2.2.1]heptyl group), a bicyclo[1.1.1]pentyl group, abicyclo[2.1.1]hexyl group, and a bicyclo[2.2.2]octyl group. The term“C₃-C₁₀ cycloalkylene group” as used herein refers to a divalent grouphaving the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to amonovalent cyclic group that further includes, in addition to a carbonatom, at least one heteroatom as a ring-forming atom and has 1 to 10carbon atoms, and examples thereof include a 1,2,3,4-oxatriazolidinylgroup, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. Theterm “C₁-C₁₀ heterocycloalkylene group” as used herein refers to adivalent group having the same structure as the C₁-C₁₀ heterocycloalkylgroup.

The term “C₃-C₁₀ cycloalkenyl group” as used herein refers to amonovalent cyclic group that has 3 to 10 carbon atoms and at least onecarbon-carbon double bond in the ring thereof and no aromaticity, andexamples thereof include a cyclopentenyl group, a cyclohexenyl group,and a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylene group” asused herein refers to a divalent group having the same structure as theC₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein refers to amonovalent cyclic group that has, in addition to a carbon atom, at leastone heteroatom as a ring-forming atom, 1 to 10 carbon atoms, and atleast one carbon-carbon double bond in the cyclic structure thereof.Examples of the C₁-C₁₀ heterocycloalkenyl group include a4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, anda 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylenegroup” as used herein refers to a divalent group having the samestructure as the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent grouphaving a carbocyclic aromatic system having 6 to 60 carbon atoms, andthe term “C₆-C₆₀ arylene group” as used herein refers to a divalentgroup having a carbocyclic aromatic system having 6 to 60 carbon atoms.Examples of the C₆-C₆₀ aryl group include a phenyl group, a pentalenylgroup, a naphthyl group, an azulenyl group, an indacenyl group, anacenaphthyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenylgroup, a heptalenyl group, a naphthacenyl group, a picenyl group, ahexacenyl group, a pentacenyl group, a rubicenyl group, a coronenylgroup, and an ovalenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀arylene group each include two or more rings, the two or more rings maybe fused to each other.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalentgroup having a heterocyclic aromatic system that has, in addition to acarbon atom, at least one heteroatom as a ring-forming atom, and 1 to 60carbon atoms. The term “C₁-C₆₀ heteroarylene group” as used hereinrefers to a divalent group having a heterocyclic aromatic system thathas, in addition to a carbon atom, at least one heteroatom as aring-forming atom, and 1 to 60 carbon atoms. Examples of the C₁-C₆₀heteroaryl group include a pyridinyl group, a pyrimidinyl group, apyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinylgroup, a benzoquinolinyl group, an isoquinolinyl group, abenzoisoquinolinyl group, a quinoxalinyl group, a benzoquinoxalinylgroup, a quinazolinyl group, a benzoquinazolinyl group, a cinnolinylgroup, a phenanthrolinyl group, a phthalazinyl group, and anaphthyridinyl group. When the C₁-C₆₀ heteroaryl group and the C₁-C₆₀heteroarylene group each include two or more rings, the two or morerings may be condensed with each other.

The term “monovalent non-aromatic condensed polycyclic group” as usedherein refers to a monovalent group (for example, having 8 to 60 carbonatoms) having two or more rings condensed with each other, only carbonatoms as ring-forming atoms, and non-aromaticity in its entire molecularstructure. Examples of the monovalent non-aromatic condensed polycyclicgroup include an indenyl group, a fluorenyl group, a spiro-bifluorenylgroup, a benzofluorenyl group, an indenophenanthrenyl group, and anindenoanthracenyl group. The term “divalent non-aromatic condensedpolycyclic group” as used herein refers to a divalent group having thesame structure as the monovalent non-aromatic condensed polycyclicgroup.

The term “monovalent non-aromatic condensed heteropolycyclic group” asused herein refers to a monovalent group (for example, having 1 to 60carbon atoms) having two or more rings condensed to each other, at leastone heteroatom other than carbon atoms, as a ring-forming atom, andnon-aromaticity in its entire molecular structure. Examples of themonovalent non-aromatic condensed heteropolycyclic group include apyrrolyl group, a thiophenyl group, a furanyl group, an indolyl group, abenzoindolyl group, a naphthoindolyl group, an isoindolyl group, abenzoisoindolyl group, a naphthoisoindolyl group, a benzosilolyl group,a benzothiophenyl group, a benzofuranyl group, a carbazolyl group, adibenzosilolyl group, a dibenzothiophenyl group, a dibenzofuranyl group,an azacarbazolyl group, an azafluorenyl group, an azadibenzosilolylgroup, an azadibenzothiophenyl group, an azadibenzofuranyl group, apyrazolyl group, an imidazolyl group, a triazolyl group, a tetrazolylgroup, an oxazolyl group, an isoxazolyl group, a thiazolyl group, anisothiazolyl group, an oxadiazolyl group, a thiadiazolyl group, abenzopyrazolyl group, a benzimidazolyl group, a benzoxazolyl group, abenzothiazolyl group, a benzoxadiazolyl group, a benzothiadiazolylgroup, an imidazopyridinyl group, an imidazopyrimidinyl group, animidazotriazinyl group, an imidazopyrazinyl group, an imidazopyridazinylgroup, an indenocarbazolyl group, an indolocarbazolyl group, abenzofurocarbazolyl group, a benzothienocarbazolyl group, abenzosilolocarbazolyl group, a benzoindolocarbazolyl group, abenzocarbazolyl group, a benzonaphthofuranyl group, abenzonaphthothiophenyl group, a benzonaphthosilolyl group, abenzofurodibenzofuranyl group, a benzofurodibenzothiophenyl group, and abenzothienodibenzothiophenyl group. The term “divalent non-aromaticcondensed heteropolycyclic group” as used herein refers to a divalentgroup having the same structure as the monovalent non-aromatic condensedheteropolycyclic group.

The term “C₆-C₆₀ aryloxy group” as used herein refers to —OA₁₀₂ (whereinA₁₀₂ is the C₆-C₆₀ aryl group), and the term “C₆-C₆₀ arylthio group” asused herein refers to —SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ aryl group).

The term “R_(10a)” as used herein refers to:

deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or anitro group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, ora C₁-C₆₀ alkoxy group, each unsubstituted or substituted with deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, aC₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂),—B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), —P(═O)(Q₁₁)(Q₁₂), or anycombination thereof;

a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀aryloxy group, or a C₆-C₆₀ arylthio group, each unsubstituted orsubstituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, a C₁-C₃₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group,a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthiogroup, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁),—S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or any combination thereof; or

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂).

Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃ and Q₃₁ to Q₃₃ used herein may eachindependently be: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxylgroup; a cyano group; a nitro group; a C₁-C₃₀ alkyl group; a C₂-C₃₀alkenyl group; a C₂-C₃₀ alkynyl group; a C₁-C₆₀ alkoxy group; or aC₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, eachunsubstituted or substituted with deuterium, —F, a cyano group, a C₁-C₃₀alkyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a biphenyl group, orany combination thereof.

The term “heteroatom” as used herein refers to any atom other than acarbon atom. Examples of the heteroatom include O, S, N, P, Si, B, Ge,Se, and any combination thereof.

The term “Ph” as used herein refers to a phenyl group, the term “Me” asused herein refers to a methyl group, the term “Et” as used hereinrefers to an ethyl group, the term “ter-Bu” or “Bu^(t)” as used hereinrefers to a tert-butyl group, and the term “OMe” as used herein refersto a methoxy group.

The term “biphenyl group” as used herein refers to “a phenyl groupsubstituted with a phenyl group.” In other words, the “biphenyl group”is a substituted phenyl group having a C₆-C₆₀ aryl group as asubstituent.

The term “terphenyl group” as used herein refers to “a phenyl groupsubstituted with a biphenyl group”. In other words, the “terphenylgroup” is a substituted phenyl group having, as a substituent, a C₆-C₆₀aryl group substituted with a C₆-C₆₀ aryl group.

The maximum number of carbon atoms in the substituent definition is notparticularly limited. In an embodiment, a case where the maximum numberof carbon atoms in a C₁-C₆₀ alkyl group is 60 is merely an example, anddefinition of the alkyl group applies equally to a C₁-C₂₀ alkyl group.The same is true for other cases.

* and *′ as used herein, unless defined otherwise, each refer to abinding site to a neighboring atom in a corresponding formula.

Hereinafter, a light-emitting device according to an embodiment of thedisclosure will be described in detail with reference to Examples.

EXAMPLES

Manufacture of Light-Emitting Device

Comparative Example 1

An anode (ITO) was patterned on a substrate according to a first,second, and third subpixels, and a pixel insulating film was formed atan edge portion.

HAT-CN as a known material was vacuum-deposited on exposed anodes toform a hole injection layer having a thickness of 100 Å, and TAPC as ahole transport compound was vacuum-deposited thereon to form a holetransport layer having a thickness of 300 Å.

N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1-biphenyl]-4,4′-diamine (TPD)was formed on the hole transport layer of the first subpixel to form afirst auxiliary layer having a thickness of 700 Å.

Alq₃ and Ir(phq)₃ were co-deposited on the first auxiliary layer at aweight ratio of 97:3 to form a red emission layer having a thickness of400 Å.

N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine (NPB) was formed on the holetransport layer of the second subpixel to form a second auxiliary layerhaving a thickness of 300 Å.

Alq₃ and Ir(3′,5′, 4-mppy)₂tmd were co-deposited on the second auxiliarylayer at a weight ratio of 90:10 to form a green emission layer having athickness of 300 Å.

DPVBi and perylene were co-deposited on the hole transport layer of thethird subpixel at a weight ratio of 99:1 to form a blue emission layerhaving a thickness of 200 Å.

TPBi was deposited on the emission layer to form an electron transportlayer, as a common layer, having a thickness of 550 Å.

LiF was deposited on the electron transport layer to form an electroninjection layer having a thickness of 8 Å.

Al was deposited on the electron transport layer to form an electrodehaving a thickness of 1,000 Å.

Compound 1 was deposited on the electrode to form a first capping layerhaving a thickness of 60 nm.

Example 1

A light-emitting device was manufactured in the same manner as inComparative Example 1, except that a first capping layer was formed tohave a thickness of 80 nm, and Compound 7 was deposited on the firstcapping layer to additionally form a second capping layer having athickness of 60 nm.

Example 2

A light-emitting device was manufactured in the same manner as inComparative Example 1, except that a first capping layer was formed tohave a thickness of 80 nm, and Compound 7 was deposited on the firstcapping layer to additionally form a second capping layer having athickness of 80 nm.

Example 3

A light-emitting device was manufactured in the same manner as inComparative Example 1, except that a first capping layer was formed tohave a thickness of 80 nm, and Compound 7 was deposited on the firstcapping layer to additionally form a second capping layer having athickness of 100 nm.

Example 4

A light-emitting device was manufactured in the same manner as inComparative Example 1, except that a first capping layer was formed tohave a thickness of 80 nm, and Compound 7 was deposited on the firstcapping layer to additionally form a second capping layer having athickness of 120 nm.

With respect to the light-emitting devices manufactured according toExamples 1 to 4 and Comparative Example 1, efficiency according to R, G,and B and efficiency of White were measured and shown in Table 1.

TABLE 1 First Second capping capping layer (nm) layer (nm) [Refractive[Refractive index at index at Efficiency ratio (Cd/A@420nit) 550 nm] 550nm] Red Green Blue White Comparative 60  0 100% 100% 100% 100% Example 1[2.01] Example 1 80  60 108% 114% 100% 107% [2.01] [1.40] Example 2 80 80 116% 122% 104% 110% [2.01] [1.40] Example 3 80 100 123% 125% 112%120% [2.01] [1.40] Example 4 80 120 118% 123% 105% 113% [2.01] [1.40]

In a light-emitting device according to an embodiment, without anincrease in efficiency resulting from improvement of compounds used inthe interlayer between the electrodes, the capping layers after thecathode were appropriately adjusted such that the efficiency wasincreased only by optical enhancement. Referring to Table 1, it wasconfirmed that, compared to the light-emitting device of the ComparativeExample, the light-emitting devices of the disclosure show an excellentresult.

A refractive index was adjusted to thereby increase light extractionefficiency, and thus the light-emitting device according to anembodiment has increased light emission efficiency.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments. While embodiments have been describedwith reference to the figures, it will be understood by those ofordinary skill in the art that various changes in form and details maybe made therein without departing from the spirit and scope as definedby the following claims.

What is claimed is:
 1. A light-emitting device comprising: a firstelectrode; a second electrode facing the first electrode; an interlayerdisposed between the first electrode and the second electrode, theinterlayer including an emission layer; a first capping layer; and asecond capping layer, wherein a refractive index of the first cappinglayer is greater than a refractive index of the second capping layer,and the first capping layer and the second capping layer are each anorganic layer.
 2. The light-emitting device of claim 1, wherein thefirst capping layer contacts the second capping layer.
 3. Thelight-emitting device of claim 1, wherein the first capping layercontacts the second electrode.
 4. The light-emitting device of claim 1,wherein the first capping layer is disposed outside the secondelectrode.
 5. The light-emitting device of claim 1, wherein the firstelectrode is an anode, the second electrode is a cathode, the interlayerfurther comprises a hole transport region disposed between the firstelectrode and the emission layer, and the hole transport regioncomprises a hole injection layer, a hole transport layer, an electronblocking layer, or a combination thereof.
 6. The light-emitting deviceof claim 1, wherein the first electrode is an anode, the secondelectrode is a cathode, the interlayer further comprises an electrontransport region disposed between the emission layer and the secondelectrode, and the electron transport region comprises a hole blockinglayer, an electron transport layer, an electron injection layer, or acombination thereof.
 7. The light-emitting device of claim 1, wherein arefractive index of the first capping layer is in a range of about 1.7to about 2.2, at a wavelength of about 550 nm.
 8. The light-emittingdevice of claim 1, wherein a refractive index of the second cappinglayer is in a range of about 1.2 to about 1.7, at a wavelength of about550 nm.
 9. The light-emitting device of claim 1, wherein a thickness ofthe second capping layer is greater than a thickness of the firstcapping layer.
 10. The light-emitting device of claim 1, wherein athickness of the first capping layer is in a range of about 60 nm toabout 100 nm.
 11. The light-emitting device of claim 1, wherein athickness of the second capping layer is in a range of about 40 nm toabout 120 nm.
 12. The light-emitting device of claim 1, wherein thefirst capping layer comprises a compound represented by Formula
 1.

wherein in Formula 1, R₁ to R₆, Ar₁, and Ar₂ are each independentlyselected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted orsubstituted with at least one R_(10a), a C₂-C₆₀ alkenyl groupunsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkynylgroup unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀alkoxy group unsubstituted or substituted with at least one R_(10a), aC₃-C₆₀ carbocyclic group unsubstituted or substituted with at least oneR_(10a), a C₁-C₆₀ heterocyclic group unsubstituted or substituted withat least one R_(10a), a C₆-C₆₀ aryloxy group unsubstituted orsubstituted with at least one R_(10a), a C₆-C₆₀ arylthio groupunsubstituted or substituted with at least one R_(10a), —B(Q₁)(Q₂),—C(═O)(Q₁)_(l)-Si(Q₁)(Q₂)(Q₃), and —P(═O)(Q₁)(Q₂), X is selected from aC₃-C₆₀ carbocyclic group unsubstituted or substituted with at least oneR_(10a) and a C₁-C₆₀ heterocyclic group unsubstituted or substitutedwith at least one R_(10a), m is an integer from 1 to 3, a3 and a4 areeach independently an integer from 1 to 3, a5 and a6 are eachindependently an integer from 1 to 4, when a3 is 2 or more, a pluralityof R₃(s) are identical to or different from each other, when a4 is 2 ormore, a plurality of R₄(s) are identical to or different from eachother, when a5 is 2 or more, a plurality of R₅(s) are identical to ordifferent from each other, when a6 is 2 or more, a plurality of R₆(s)are identical to or different from each other, and R_(10a) is: deuterium(-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitrogroup; a C₁-C₆₀ alkyl group, a C₂-C₃₀ alkenyl group, a C₂-C₃₀ alkynylgroup, or a C₁-C₃₀ alkoxy group, each unsubstituted or substituted withdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, —Si(Q₁₁)(Q₁₂)(Q₁₃),—N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), —P(═O)(Q₁₁)(Q₁₂),or a combination thereof; a C₃-C₆₀ carbocyclic group, a C₁-C₆₀heterocyclic group, a C₆-C₆₀ aryloxy group, or a C₆-C₆₀ arylthio group,each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, aC₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, aC₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂),—B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or acombination thereof; or —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂),—C(═O)(Q₃₁), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂), wherein Q₁ to Q₃, Q₁₁ toQ₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each independently: hydrogen;deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitrogroup; a C₁-C₆₀ alkyl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynylgroup; a C₁-C₆₀ alkoxy group; or a C₃-C₆₀ carbocyclic group or a C₁-C₆₀heterocyclic group, each unsubstituted or substituted with deuterium,—F, a cyano group, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a phenylgroup, a biphenyl group, or a combination thereof.
 13. Thelight-emitting device of claim 12, wherein R₃ to R₆ are eachindependently hydrogen or deuterium.
 14. The light-emitting device ofclaim 1, wherein the second capping layer comprises a compoundrepresented by Formula 2:

wherein in Formula 2, R₁₁ to R₂₅ are each independently selected fromhydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with atleast one R_(10a), a C₂-C₆₀ alkenyl group unsubstituted or substitutedwith at least one R_(10a), a C₂-C₆₀ alkynyl group unsubstituted orsubstituted with at least one R_(10a), a C₁-C₆₀ alkoxy groupunsubstituted or substituted with at least one R_(10a), a C₃-C₆₀carbocyclic group unsubstituted or substituted with at least oneR_(10a), a C₁-C₆₀ heterocyclic group unsubstituted or substituted withat least one R_(10a), a C₆-C₆₀ aryloxy group unsubstituted orsubstituted with at least one R_(10a), a C₆-C₆₀ arylthio groupunsubstituted or substituted with at least one R_(10a), —B(Q₁)(Q₂),—C(═O)(Q₁), —Si(Q₁)(Q₂)(Q₃), and —P(═O)(Q₁)(Q₂), two neighboringsubstituents of R₁₁ to R₁₅ are connected to form a ring group, twoneighboring substituents of R₁₆ to R₂₀ are connected to form a ringgroup, or two neighboring substituents of R₂₁ to R₂₅ are connected toform a ring group, and R_(10a) is: deuterium (-D), —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, or a nitro group; a C₁-C₆₀ alkyl group, aC₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₃₀ alkoxy group,each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, a C₃-C₆₀ carbocyclicgroup, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀arylthio group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂),—C(═O)(Q₁₁)_(l)-S(═O)₂(Q₁₁), —P(═O)(Q₁₁)(Q₁₂), or a combination thereof;a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀aryloxy group, or a C₆-C₆₀ arylthio group, each unsubstituted orsubstituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group,a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthiogroup, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁),—S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or a combination thereof; or—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂), wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ toQ₂₃, and Q₃₁ to Q₃₃ are each independently: hydrogen; deuterium; —F;—Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C₁-C₆₀alkyl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀alkoxy group; or a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclicgroup, each unsubstituted or substituted with deuterium, —F, a cyanogroup, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a phenyl group, abiphenyl group, or a combination thereof.
 15. The light-emitting deviceof claim 14, wherein the ring group is represented by Formula 2-1:

wherein in Formula 2-1, Y is —N(R₃₁) or —C(R₃₂)(R₃₃), R₃₁ to R₃₃ areeach independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted orsubstituted with at least one R_(10a), a C₃-C₆₀ carbocyclic groupunsubstituted or substituted with at least one R_(10a), and a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least oneR_(10a), R₃₂ and R₃₃ are optionally connected to form a ring, a21 is aninteger from 1 to 4, * indicates a binding site to a neighboring atom,and R_(10a) is: deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, acyano group, or a nitro group; a C₁-C₆₀ alkyl group, a C₂-C₃₀ alkenylgroup, a C₂-C₃₀ alkynyl group, or a C₁-C₃₀ alkoxy group, eachunsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, a C₃-C₆₀ carbocyclicgroup, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀arylthio group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂),—C(═O)(Q₁₁)_(l)-S(═O)₂(Q₁₁), —P(═O)(Q₁₁)(Q₁₂), or a combination thereof;a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀aryloxy group, or a C₆-C₆₀ arylthio group, each unsubstituted orsubstituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group,a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthiogroup, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁),—S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or a combination thereof; or—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂), wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂-1 toQ₂₃, and Q₃₁ to Q₃₃ are each independently: hydrogen; deuterium; —F;—Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C₁-C₆₀alkyl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀alkoxy group; or a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclicgroup, each unsubstituted or substituted with deuterium, —F, a cyanogroup, a C₁-C₃₀ alkyl group, a C₁-C₃₀ alkoxy group, a phenyl group, abiphenyl group, or a combination thereof.
 16. The light-emitting deviceof claim 1, wherein the first capping layer comprises one of thefollowing compounds:


17. The light-emitting device of claim 1, wherein the second cappinglayer comprises one of the following compounds:


18. An electronic apparatus comprising the light-emitting device ofclaim
 1. 19. The electronic apparatus of claim 18, further comprising athin-film transistor, wherein the thin-film transistor comprises asource electrode and a drain electrode, and the first electrode of thelight-emitting device is electrically connected to at least one of thesource electrode and the drain electrode of the thin-film transistor.20. The electronic apparatus of claim 18, further comprising a colorfilter, a color conversion layer, a touch screen layer, a polarizinglayer, or a combination thereof.